Generator synchronization is an important and frequent operation in rural small hydropower station. In order to ensure that generator can be paralleled in the grid automatically,efficiently,and stably in the rural small hydropower station whose parallel in operation still needs to be accomplished manually. This paper described an automatic quasi-synchronizing device,based on 89C52 Single-chip Microcomputer(SCM) . Its hardware includes three modules and its software is structuralized. The device structure is simple,and its reliability is high and the maintenance is easy. Besides,convenient Human Machine Interface(HMI) makes the parameter setting simple and flexible. Generator synchronization is an important and frequent operation in rural small hydropower station. In order to ensure that generator can be paralleled in the grid automatically, efficiently, and stably in the rural small hydropower station whose parallel in operation still needs to be yet manually. based on 89C52 Single-chip Microcomputer (SCM). Its hardware includes three modules and its software is structuralized. The device structure is simple, and its reliability is high and the maintenance is easy. Besides, convenient Human Machine Interface (HMI) makes the parameter setting simple and flexible.