A model system was proposed based on the advanced experience at home and abroad, which was applied to agricultural water-saving zoning. The reality of agricultural water saving, water resources distribution, natural conditions, agricultural water management, project management level and pecuniary condition in Beijing were also included in this model system. The model system included several indices and each index was defined based on index categorization. These indices were also used to present the aridity soil type and ground water index distribution in the corresponding zoning. Meanwhile, ArcGIS was also combined based on the function of superposition analysis and analytic hierarchy process (AHP). The ArcGIS analysis function in each lay was defined and the weight function on each function was also defined. Through the definition, the index value on each lay and each function can be obtained. After that, the index value can be scored and classified and also multiplied with each index weight. The multiplied values were the final value result and treated as overall value which was treated as the guided line for Beijing agriculture water-saving zoning classification. Through the model system classification results, Beijing was divided into agricultural water conservation priority development area, agricultural water saving suitable development area and agricultural water saving encouraging development area. According to the model system results, the corresponding engineering measures and agronomic measures were also recommended in water-saving and can partly help the decision-maker in Beijing to optimize the agricultural water saving.