Participatory teaching method is advocated by China Education Ministry to cultivate innovative talents in the future,and its exploration in the practice course of pollution investigation is beneficial to teaching reform in environmental engineering. The implementation process of participatory teaching method in municipal sewage treatment plant was divided into four stages: analysis stage, forming program stage, implementation and monitoring program stage and evaluation and feedback program stage. The implementation process of this teaching reform was assessed comprehensively. Although this reform was facing many challenges including teaching environment, practice contents, students difference and teachers flexibility, it has also gained the understanding and respect for teachers behavior and the enhancement on students' motivation to learn on the positive side.