During the late years of the dynasty—the reigns of Emperor Wucheng and Gao Wei, traditionally viewed as a period of corruption and debauchery when the Northern Qi's once-powerful status was deteriorating—Hulü was viewed as the key pillar to the state and its army, maintaining the army's strength against the rivaling Northern Zhou and Chen dynasties.
However, the powerful officials Zu Ting and Mu Tipo, had disagreements with him and accused him of plotting treason.
In a rare case where Hulü might have exhibited some uncharacteristic overexuberance, when Murong and his lieutenant Liu Fengsheng (劉豐生) were initially defeated by Hou, Hulü and his fellow junior general Zhang Shixian (張恃顯) rebuked Murong and Liu for their defeat.
As Hulü and Zhang rode out to engage Hou, however, Murong warned them, "Do not cross the Guo River [(渦水)]."
After Gao Cheng died in 549, his brother Gao Yang took over as regent, and in 550, he had Emperor Xiaojing of Eastern Wei yield the throne to him, ending Eastern Wei and establishing Northern Qi as its Emperor Wenxuan.
In 552, when Emperor Wenxuan made an attack against the Kumo Xi tribe (in the upper Liao River drainage area), Hulü accompanied him and contributed in the victory.
Also in 560, Emperor Fei's uncle Gao Yan the Prince of Changshan, with support from, among others, Hulü Jin, killed the prime minister Yang Yin and took power.
In spring 564, Northern Zhou, in alliance with Tujue, launched a major attack on Northern Qi, attacking the secondary capital Jinyang (晉陽, in modern Taiyuan, Shanxi) from the north and Pingyang (平陽, in modern Linfen, Shanxi) from the south.
Emperor Wucheng sent Duan, Hulü, and his nephew Gao Changgong, the Prince of Lanling to relieve Luoyang, and they defeated Northern Zhou troops, killing Daxi's lieutenant Wang Xiong (王雄), forcing Daxi to retreat.
In 565, at the urging of the officials He Shikai and Zu Ting, Emperor Wucheng passed the throne to Gao Wei and created Crown Princess Hulü empress.
Around the new year 569, Emperor Wucheng died, and thereafter power was largely in the hands of his favorite (and Empress Dowager Hu's lover) He Shikai.
Around the new year 570, the Northern Zhou general Yuwen Xian put the Northern Qi city Yiyang (宜陽, in modern Luoyang, Henan) under siege, and in spring 570, Hulü was sent to resist, and he defeated Yuwen Xian.
Hulü decided to take the war to Northern Zhou elsewhere, and in winter 570, he moved north and built forts north of the Fen River (汾水, flowing through modern Linfen), taking the previously unguarded border territory into Northern Qi control.
Gao Wei did not act immediately, however, and the army approached Yecheng without receiving any words from the emperor.
The historian Li Yanshou (李延寿), in his History of Northern Dynasties, described him in this way: However, by 572, Hulü was in serious conflict with the powerful officials Zu and Mu.
Once, when he was resting at a governmental building, Zu, who was blind, rode past him without realizing that Hulü was there, and never got off the horse as demanded by customs of the time.
Emperor Wu of Northern Zhou was so pleased at the news of Hulü's death that he declared a general pardon.
In 578, after he destroyed the Northern Qi and entered Yecheng, he commented on Hulü, "If he were still alive, how can I get here?"(此人若在,朕豈能至鄴!)