With the rapid development of internet technology and protected cultivation in China, it is impending to implement a web-based information service system to spread professional agricultural knowledge. In this study, a 3-layer architecture web-based information service platform (ISP) for protected crop pests was developed using HTML, JavaScript and active server page (ASP). The platform included the information management module, the aided diagnosis module, the module of instructions for pest control, the technology BBS module, the system management module and the relative references module. Two logical algorithms, namely, identification key method and fuzzy diagnostic method, were designed for aided diagnosis of protected crop pests. The ISP could provide a technological platform for decision makers, agricultural technique extension workers and farmers. It is favorable to the effective management of protected crop pests.