With the security industry developing rapidly and the number of security systems increasing continuously in recent years, security systems provide a positive effect on society security in China, but many of them became vulnerable or even useless because of the problem of irrational allocation of resources. In order to evaluate security system efficiency to avoid these problems, the hierarchy structure of the risk assessment is constructed firstly. Secondly, we use AHP method and Fuzzy logical method, the formula of risk degree and entropy-weight coefficients are put forward to estimate the crime prevention system objectively. The study of the case shows that the method can be easily used to the risk assessment of the crime prevention system and its results conform to the actual situation.