Cao Cao's "relying on the emperor to make the princes" gained the advantage of political discourse, while building water conservancy and implementing "wasteland system" laid a material foundation for unifying northern China. Cao Cao adheres to the policy of "appointing talents and appointing talents, and recruiting talents in many ways". Militarily, Cao Cao wrote more than 100,000 words and edited thirteen articles of Sun Tzu's Art of War, which won the attention of the Art of War. He spent most of his life in battles, commanding battles "because of strange things, the enemy won and became like a god." During the 14 years from the age of 39 to 53, he experienced more than 50 wars, successively destroying Yang Feng, Han Xian, Yuan Shao, Yuan Shu, Tao Qian and Lu Bu, taking over Zhang Xiu, conquering Wuhuan and unifying the north. After the defeat of Chibi, Cao Cao still beat Hefei and chased Ma Chao in the spirit of "martyrs are more courageous in their twilight years". According to Guan Zhong, he pacified Hexi and Longyou and consolidated the unification of the north. In literature, Cao Cao advocated a new style and created many excellent poems, which played a decisive role in the formation and development of Jian 'an literature.