He initially served in the military in the late Liang dynasty, and gradually grew in stature and fame during the reigns of each of the emperors of Chen.
In winter 549, the ambitious general Chen Baxian raised an army at Guang Province (廣州, roughly modern Guangdong) and planned to march north, eventually to head to Jiankang to attack Hou.
Xiao experienced a surge of fury, roaring fiercely and single-handedly fighting through the frontlines to save Hou from Northern Qi soldiers, and no men could stop him.
It was as the governor of Bashan Commandery that Xiao served under the major general Wu Mingche in 573 as Wu, commissioned by Emperor Wen's brother Emperor Xuan, led a campaign against Northern Qi, seeking to capture the region between the Yangtze River and the Huai River.
The Chen forces under Wu were intimidated by a small vanguard force in the Northern Qi army, commanded by the Xianbei generals Wei Pohu (尉破胡) and Zhangsun Honglüe (長孫洪略), this elite squad consisted of tens of sturdy looking fighters with great physical strength and they were all above 1.9 metres tall, and accompanied by a sharpshooting Eurasian bowsman from the Western Regions (Xiyu).
Wu informed Xiao of this, while praising him as having fortitude equivalent to Guan Yu and Zhang Fei.
In spring 578, the Northern Zhou general Wang Gui arrived with a force to lift the siege, and he, as his first step, cut off Wu's supply route (and escape path).
Wu subordinates suggested destroying the levee near Pengcheng so that the area would flood, allowing them to escape by ships.
In 580, after Northern Zhou captured the region between the Yangtze and Huai from Chen, Emperor Xuan made an attempt to recapture the territory, and Xiao served in the campaign along with Emperor Xuan's nephew Chen Huiji (陳慧紀), but after he was unable to capture Guangling (廣陵, in modern Huaiyin, Jiangsu), he withdrew.
He subsequently made Xiao the governor of Southern Xu Province (南徐州, roughly modern Zhenjiang, Jiangsu), to defend against potential attacks by Northern Zhou's successor state Sui dynasty from Guangling.
In spring 589, when Xiao was at Jiankang, the Sui general Heruo Bi (賀若弼) took the chance to cross the Yangtze (as part of the overall campaign by Emperor Wen of Sui to destroy Chen and reunited China) and captured Jingkou (京口, the capital of Southern Xu Province).
Chen Shubao agreed, despite warnings by another major general, Ren Zhong (任忠), not to engage Heruo.
Emperor Wen made Xiao Mohe a general, but unlike the situation with Zhou Luohou, did not give him great responsibilities.
His sons were not killed but were seized as imperial servants, and his subordinate Chen Zhishen (陳智深) took his body and gave it a proper burial.