In modern society, computer network has already been covered. In people's daily lives, the information technology industries have become ubiquitous. In the civil and military, commercial's security which is playing an important role is very prominent. The key generation algorithm of AES was introduced, the weaknesses of the key generation design of AES were investigated. According to the key demand put forward a kind of new design idea and this designing strategy was developed, which can be used to improve the key generation algorithm of AES. An analysis shows that such improvement can enhance the safety of the original algorithm without reducing its efficiency.