Venus is a famous bane and punished star in Han dynasty and ancient Chinese astrology, controlling the military and killing, and its divination had close relation with military. The astronomical phenomenon of“deviating seriously from normal orbit”, such as Venus appearing in day and passing through meridian, entering the Supreme Palace Enclosure, and joining or violating with other planets is regarded as the sign of war and the social order or disorder. It becomes an important reference of military decision and an excuse or tool with which the ministers and Confucian scholars persuaded the emperors to implement benevolence and reform officials. It plays a noticeable role in social and military area of Han dynasty.