The networked software is composed of heterogeneous Web services which are distributed on the Internet. Service trustworthiness is in constant change under the influence of dynamic and open environment. To solve the problem that Web service trustworthy evaluation is difficult to adapt dynamic environment, this study developed a dynamic trustworthy evaluation based on information entropy and correction metrics. It mined deeply the objective information in fuzzy matrix and modified the subjective weights that are susceptible to human factors. Considering the impact of the running environment on the trustworthiness of the current service, it added correction metrics and external metrics affected by feedback to improve self-adaptability of the evaluation model. Finally, simulation experiments based on a map service show that the DTMIECM model possesses feasibility in trustworthy measurement. It can adapt to unstable environment and reconfigure service to improve trustworthiness of the whole system.