Trust mechanism will be an important trend in the field of security for open network. But, as an important factor risk is little considered in trust model. In this paper, Further works are done in trust and risk separately. In course of trust propagation, direct interaction information of the middle recommendation node is presented, which expresses the importance of subjective factor. About risk mechanism, two important factors are considered to improve the corresponding algorithms: length-limit of the risk propagation path and pre-operation process before integrating these paths. With the help of fuzzy logic technology, the trusted decision mechanism is presented which is based on trust and risk. Experimental results and some cases show that the new trusted decision mechanism is reasonable and high-powered.