The dream of the Spring and Autumn Period refers to an unrealistic idea, because during the Spring and Autumn Period, monarchs of all countries competed for hegemony. During the Warring States period, the goal of Qin was clear, that is, to destroy the six countries and rule the world, while the goal of the other six countries was still hegemony. They were still dreaming of the Spring and Autumn Period, so they had the Spring and Autumn Period dream. The difference in guiding ideology between Qin State and other six countries is the fundamental reason why Qin State finally unified the six countries.