Wireless sensor networks (WSN) have been widely used in various applications. Since their sensor nodes are resource-constrained, key management is one of the most challenging issues in design of WSN. Currently, various efficient lightweight key management schemes have been proposed to enable encryption and authentication in WSN for different application scenarios. According to different requirements, it is important to select the trustworthy key management schemes in a WSN for setting up a fully trusted WSN mechanism. In this context, adaptive methods are required to evaluate those schemes. In this paper, we exploit Analytic Hierarchy Process (AHP) to help with the complex decision. Specifically, we consider the following performance criteria: scalability, key connectivity, resilience, storage overhead, processing overhead and communication overhead. Our method is able help choosing a suitable scheme for given requirements.