Abstract: In the light of the complexity and real-timeliness of water use management in farmland irrigation, the software for water-saving irrigation management and decision support system was developed. Based on the collected information such as weather, soil moisture, crops and water resources situation, the water requirement of the crop was calculated by using the method of crop coefficient. According to the decision-making models of soil moisture, the irrigation prediction could be made to determine the accurate irrigation date and optimum irrigation amount by the system. Meanwhile, the irrigation equipments were automatically controlled and monitored to realize the aim of high-efficiency and water saving according to the results, which were obtained from the decision-making model. The system not only had the functions of input, editing, querying, statistics, outputting, etc., but also could provide the decision support of irrigation optimization and optimal allocation of water resources for irrigation management departments and water users. The system could also make the precision irrigation schemes. It can provide with the functions such as the consultation of water-saving irrigation mode, the selection of the optimum irrigation schemes, and guiding optimum irrigation for users in irrigation districts. The system has higher value in its application and popularization.