Empirical analysis: first, he unified the north, reclaimed land, built water conservancy projects and implemented the system of official selling salt and iron, which played a positive role in social and economic recovery and economic consolidation. Secondly, he is an outstanding strategist and writer, and Cao Cao's poems such as "Although Returning to Life" and "Short Songs" are still in textbooks. His achievements in the literary world are also recognized. Militarily, Cao Cao is also resourceful, and he can always improvise in strategy and tactics. When fighting, Cao often makes decisions according to the situation of the enemy and ourselves, which is changeable. The third is his character. He didn't kill Guan Yu, which shows that he is still very talented. Although Cao Cao "would rather I take the blame for the whole world", he still made some achievements in some things. On the other hand, Cao Cao killed innocent people. When suppressing the Yellow Scarf Uprising and Xuzhou, he killed people indiscriminately, and many innocent people were implicated. I think an outstanding politician should be different.