It is important to construct a reliable service environment with security and credibility in e-service. The information gap between services providers and requestors on the credibility of services may give chances for bad behaviors. Requestors wandered outside of the web-based system not only for the security matters but also for their distrust of the services on the internet. In order to bridge the information asymmetry gap and construct a reliable service environment, a service detecting model with quality certification and trust evaluation is proposed in this paper. By applying the model it is ensured that the available services in e-service system are trustable services. The most credible service is recommended according to services' comprehensive credible degrees calculated by their quality and trust values. The case analyses show that the requestors' confidence of using services was enhanced and credible services with high quality were reused in the simulation platform.