Trust management is now one of the interesting research topics in the field of web security. Firstly, several existing trust models are analyzed. Aiming at flaws of these models, the subject trust model based on fuzzy comprehensive evaluation is proposed, thus solving the evaluation problem of subjects trust degree in trust model. An effective evaluation strategy for trust degree vector of subject trust model is given. Finally, a concrete example is provided and has proved the rationality and feasibility of the model.