Abstract: Aiming at the problems of drainage and irrigation machinery in China, the structure and the working principle of the rotator pump which can be widely used in agriculture were given. The instantaneous flow characteristics and the instantaneous flow pulsation of the pump were analyzed. The flow pulsation rate of the pump was far smaller than that of common gear pump. The engaging power of the pump was zero. The results that the new kind of pump has bigger displacement and higher pressure are obtained and on some conditions it can be widely used in agricultural products processing in China. The research results will be application to the design of the new type of water pump.