Trust model is the basis of the entire network security system. It determines the form of trust used in the network and the risk caused by the form. Furthermore, it provides the framework for establishing and managing the trust relations. It can clearly be seen that the study of trust model in the network security is considerably significant. This paper mainly analyses the trust mechanism, the certification process and their advantages and disadvantages about the various types of trust models based on multi-CA. It also points out the main reasons why trust models influence the network information security. By summing up and comparison, this paper points out the future research strategies and development trend of the trust models based on multi-CA.