In the Battle of the Lake, Liu's secretary was Mao. At that time, there was a shortage of a Russian translation secretary, and Mao was the best choice. Finally, Mao concealed his true identity, became Liu's secretary, and went to the Korean battlefield with the troops.

Mao had been studying abroad before, but after returning to China, due to the lack of Russian translation in the War to Resist US Aggression and Aid Korea, Mao became the best choice. Mao concealed his true identity, and Liu, the incarnation secretary, went to the Korean battlefield with the troops. Originally, Mao was in the rear, and the risk factor was not great. But at that time, the telegraph signal sent by their headquarters was noticed by the American army, so the air raid was coming.

When the American army dropped bombs on the headquarters, Mao and another comrade who failed to evacuate fell in the war, so he died. Mao's life was very short, and he finally ended his life on the Korean battlefield. Only after Mao Anying died did everyone know his true identity. Everyone was surprised and felt sorry for Mao.