Abstract: Aquatic breeding and reclamation in polder are the main problems in the Lixia lake region. Preparing plan of returning polder to lake and its implementation are the primary means to solve the problems such as flood control and drainage, water environment and water ecology in the Lixia lake region. In order to promote the implementation of returning polder to lake, it is necessary to study its content and influence. This paper presents the content of returning polder to lake in detail, and analyzes the influence on hydrodynamics and water environment of the lake environment. The results show that returning polder to lake helps to restore the water, enhance the hydrodynamic conditions, improve the self-purification ability and wetland environment of the lake, which have positive effects on the restoration and maintenance of the lake ecology. The research results provide references for drafting returning polder to lake plan and its implementation.