The Law on People’s Assessors has broad regulations on the scope of participation in trials，and the participation mechanism has too much authoritative factors. Excessive scope of participation of people’s assessors will not only waste judicial resources，but also bring about the old problems of system function dislocation and formalization. In order to give full play to the judicial democracy function of the people’s assessors regime in improving the judicial integrity and absorbing the wisdom of ordinary people，it is necessary to limit the participation scope of people’s assessors in the trial. People’s assessors should participate in those major and complex criminal cases with the application from the defendant and the victim. Limiting the scope of people’s assessors’ participation in the trial is conducive to the exertion of judicial democracy function，saving judicial resources and reducing the difficulty of distinguishing facts from legal issues.