The quality control step of precipitation processing system of the WSR-88D，and deeply knowledge of the precipitation preprocessing algorithm，precipitation rate algorithm,precipitation accumulation algorithm and precipitation adjustment algorithm are studied. The study and setting of varieties of precipitation adaptable parameters are made based on the geography and climate of Shanghai region，the station condition and operation，so as to expect to get the best precipitation estimation. With the optimization of the WSR-88D precipitation product，the precipitation estimation accuracy of the system has been improved. It can give some useful reference to the CINRAD installing throughout the country.