After the Mangshan War, Gao Wei, Queen of the Northern Qi Dynasty, said to Gao Changgong, "What should you do if you rush into the enemy line like this?" Gao Changgong replied, "State affairs are our family affairs. I wouldn't have thought of that on the battlefield. " Then Lord Gauguin began to doubt Gao Changgong, because he said "housework" and heard soldiers sing "the ensemble of the warrior Lan Ling".

In the Battle of Dingyang, Gao Changgong took the place of Duan Shao to command the army, but he often took bribes and collected property. His cronies wanted to ask him, "Your Majesty is trusted by the imperial court. Why are you so greedy?" Gao Changgong didn't answer. Xiang Xiang went on to say, "Is it because Mangshan has achieved great success that you are afraid of serving Gao Zhen, jealous and want to do something that people look down upon?" Gao Changgong said yes. Xiang Xiang said, "If the court hates you, it will be more likely to be regarded as a crime. This is not to avoid disaster but to bring disaster! " Gao Changgong leaned down and cried and asked Xiang Xiang for a solution. Xiang Xiang said, "You have made great contributions before, but you still won the battle this time. Your reputation is too great. You'd better stay at home on the pretext of being ill and don't mind the political affairs of the country. " Gao Changgong listened to his plan, but there was no way to retire smoothly. When the imperial court used force against Chen Chao, Gao Changgong was afraid of being appointed as a general again, and said with a sigh, "There was a carbuncle on his face last year, so why didn't it come out now!" Since then, I have been sick and refused treatment.

In May of the fourth year of Wuping (573), the late ruler Gao Wei sent envoys to send poisoned wine to Gao Changgong. Gao Changgong said to his Princess Zheng (Princess Lanling), "I am so loyal to my country. Where can I live up to the emperor and give me poisoned wine? " Zheng replied, "Why not explain it to the emperor himself?" Gao Changgong asked, "How could the Emperor receive me?" So he drank poisoned wine and died. After his death, the court posthumously awarded him the title of Qiu, posthumous title Wu.