In his 29 years of rule, Emperor Wen largely continued the grand plan of his father and some of the land policies of the Jin Dynasty.

However, Emperor Wen was faulted for making repeated failed attempts to attack rival Northern Wei and using the wrong strategies in doing so, weakening his state toward the end of his rule.

However, Wang Hua pointed out that the coup leaders were in a collective leadership, and the balance of power ensured that they could not commit treason.

He also hinted at disapproval of their actions by recalling the wives and mothers of Emperor Shao and Liu Yizhen to the capital and treating them with honor.

In 425, Xu and Fu offered to resign, and Emperor Wen approved and began to handle important matters of state himself.

However, Emperor Wen was resentful that Xu, Fu, and Xie had killed his two older brothers, and in late 425 planned to destroy them, particularly at the urging of Wang Hua and the general Kong Ningzi (孔寧子).

He therefore mobilized troops and publicly declared that he was going to attack rival Northern Wei, but was privately preparing to arrest Xu and Fu while engaging in a military campaign against Xie, then the governor of Jing Province.

That year, Emperor Wen's maternal grandmother Lady Su died, and he mourned her greatly, wanting to posthumously create her titles, but because of opposition by the key official Yin Jingren (殷景仁), he did not do so.

Emperor Taiwu of Northern Wei, when informed by Emperor Wen's messengers that all Emperor Wen was interested in was to recover the provinces south of the Yellow River, retorted angrily that he would withdraw but return in the winter once the Yellow River froze, and that was what he initially did—withdrawing his armies south of the Yellow River to areas north, allowing Liu Song to recover the four key cities of Luoyang, Hulao, Huatai (滑台, in modern Anyang, Hunan), and Qiao'ao (碻磝, in modern Liaocheng, Shandong) without a fight.

With Emperor Wen's forces immobile, Northern Wei was able to attack Helian Ding and greatly damage Xia (eventually leading to its destruction in 431) absence.

Liu quickly defeated and killed Sima Feilong, but the Buddhist monk Cheng Daoyang (程道養) soon rose in succession and claimed to be the real Sima Feilong, threatening Chengdu the capital of Yi Province, and while the general Pei Fangming (裴方明) was able to repel the siege, Cheng remained a threat for several years, carrying the title of the Prince of Shu.

While the campaign was ongoing, Yang Nandang (楊難當) the ruler of Chouchi, who had been a nominal vassal to both Liu Song and Northern Wei, also attacked and occupied Liang Province (梁州, modern southern Shaanxi) in 433.

In spring 434, Emperor Wen's general Xiao Sihua (蕭思話) was able to defeat Yang Nandang's forces and recapture Liang Province.

However, Emperor Wen was unable to provide actual assistance, and Feng Hong evacuated his state and fled to Goguryeo in 436.

At that time, Tan was already on the dock ready to depart for Jiang Province, and Liu Yikang summoned him back to Jiankang and arrested him.

Emperor Wen then issued an edict falsely accusing Tan of preparing treason and executed him with his sons, but spared his grandsons.

Later in 437, the long-term rebel Cheng Daoyang the Prince of Shu was finally captured and killed, ending a seven-year rebellion.

He set up four disciplines at the university: The historian Sima Guang, author of Zizhi Tongjian, made the following commentary about Emperor Wen with regard to the status of his state at this time: Emperor [Wen] was kind and honest, humble and frugal, diligent and law-abiding, not overly critical of others and willing to accept others, but he also did not overly relax them.

During his 30 years of reign, his empire was peaceful, the population increased, and the taxes were limited to the proper amounts, with no additional levies.

In later ages, when discussions of prior administrations were made, the rule of Yuanjia [Emperor Wen's era name] was all greatly praised.Emperor Wen's attention to imperial officials' abilities could be seen partly in 439, when, according to an edict that Emperor Wu had left that his sons were to serve as the governor of Jing Province in rotation by age, he was supposed to make his brother Liu Yixuan (劉義宣) the Prince of Nanqiao the governor of Jing Province.

He then removed Liu Yikang from his prime minister post and made him the governor of Jiang Province, while restoring Yin Jingren to power.

In 445, in a famous incident, while waiting to send his brother Liu Yiji off to his new post as governor of Southern Yan Province (南兗州, modern central Jiangsu), Emperor Wen ordered his sons not to eat until dinner is served at the sendoff, but then intentionally had dinner served late, so that his sons would suffer from hunger, and then telling them, "You grew up in a rich household and do not see the people being poor.

After that feast, an alleged plot involving the official (and compiler of Book of the Later Han) Fan Ye was exposed—as it was alleged that Fan had plotted with his nephew Xie Zong (謝綜) and the deposed prime minister Li Yikang's associate Kong Xixian (孔熙先) to assassinate Emperor Wen at the feast for Liu Yiji and then making Liu Yikang emperor.

(The historian Wang Mingsheng (王鳴盛) found the alleged plot far-fetched, and believed instead that Fan had been the victim of false accusations by Xu, Yu Bingzhi (庾炳之), and He Shangzhi.)

This made Emperor Wen believe that Northern Wei's military power was waning, and he decided to launch his attack late in 450, despite oppositions by the generals Liu Kangzu (劉康祖), who believed that the campaign should begin in spring 451, Shen Qingzhi (沈慶之), who opined that Liu Song was not in shape to fight a war against Northern Wei, Xiao Sihua, and Crown Prince Shao.

Xiao considered defending Qiao'ao against the coming Northern Wei assault, but Shen persuaded him that doing so was futile, and despite orders from Emperor Wen to defend Qiao'ao, Xiao led the main forces back to Licheng (歷城, in modern Jinan, Shandong) to preserve the strength of the army.

Emperor Taiwu's nephew Tuoba Ren (拓拔仁) quickly captured Xuanhu and Xiangcheng (項城, in modern Zhoukou, Henan) and pillaging his way to Shouyang.

In spring 451, worried that his forces were being overstretched and would be attacked in the rear by the Liu Song forces garrisoned at Pengcheng and Shouyang, Emperor Taiwu began a withdraw, and on the way, insulted by the Liu Song general Zang Zhi (臧質), he put Xuyi (盱眙, in modern Huai'an, Jiangsu) under siege, and, after both sides suffered heavy losses but with the defense holding, quickly withdrew.

He therefore discussed with his high-level officials Xu Danzhi, Jiang Dan, and Wang Sengchuo (王僧綽) his planned punishment of deposing Crown Prince Shao and ordering Liu Jun to commit suicide.

Liu Shao initially gave his father the posthumous name Emperor Jing (景皇帝) with the temple name Zhongzong (中宗).