During the Southern and Northern Dynasties, Duke Jingguo of the Southern Qi Dynasty was brutally murdered. His innocent, lively, clever and intelligent daughter Mai Sui suddenly encountered a great change and lived a life of wandering and displacement. In order to avenge her family, Mai Sui hid her identity and embarked on the road of joining the army, joining the army as a daughter. She took off her red makeup and put on armor. Under the training of Shang Yizhi, the son of the former crown prince of the Southern Qi Dynasty, she relied on her intelligence and perseverance to go through hardships, overcome all difficulties, break through many difficulties, and repeatedly made military exploits. She grew step by step from a small infantryman to the commander of the Jiangbei Army, which was famous in four countries. She originally only wanted to avenge her parents by joining the army, but she gradually realized that war should not be a weapon for anyone to gain personal benefits. In order to defend his country and save the people from the suffering of war, he tried his best and was more than a man. In the battles again and again, he got to know and appreciate the enemy general Chang Yuqing and fell in love with them. Facing national hatred and family feuds, Mai Sui was ruthless for the people and gave up love for the country. He did not get entangled in personal affairs and finally realized his father's last wish and protected the country and the people.