In order to quickly and effectively compute the soil erosion modulus of more than 30000 field inves-tigation units in soil and water conservation survey(the first national water conservancy survey), water ero-sion modulus calculator software is designed and developed based on Chinese soil loss equation(CSLE) by using. NET platform of microsoft and AcrEngine development kit. By taking the data of field investigation units selected in Ansai County of Shaanxi Province as an example, the software is applied to calculate the water erosion modulus of the units and the calculated result is compared with that by operating ArcMap with manual method. Results indicate that the calculated result using water erosion modulus calculator software is accurate and reliable, and it can improve the calculation efficiency greatly. The software can be used for water erosion modulus calculation in regional soil erosion survey.