Abstract: With the development of information technology, information island has become an obstacle to information resources sharing between cross-domains. Interoperability is the key technology to solve this problem. However, establishing good trust relationship is a prerequisite for achieving the interoperation between cross-domains. Under the background of information system interoperability, and from the perspective of the organizational trust relationship, the interoperability trust is studied. On the one hand, the qualitative and quantitative factors affecting the interoperability trust are analyzed, and the trust evaluation index system is established; on the other hand, with the characteristics of local autonomy and dynamic change of interoperability, and in view of the fact that the evaluation index system of interoperability trust is characterized by the comprehensiveness, fuzziness, dynamics and multi-dimension, a dynamic and comprehensive evaluation method for interoperability trust based on fuzzy variable weighting theory is proposed and studied. Finally, the feasibility of the research results above is simulated. It is proved through analysis that the proposed method could implement dynamic change of dynamic trust and interoperability logical reconstruction based on trust. It could also provide support for interoperability access control.