Abstract: Shimen Reservoir Irrigation Area is a large-sized irrigation area in Hanzhong Plains. It is of great significance to study the water use efficiency of typical irrigated areas through water balance test to realize the mode, experience and practice of the strictest water resource management system. By conducting water balance tests of point, line and plane in irrigated area, and the quantitative relationship between water distribution and water delivery, water facilities operation, total water consumption and water consumption in each region is obtained.Based on the test data, this paper calculates the utilization efficiency of irrigation water, analyzes the water use efficiency of the irrigated area by combining the geomorphology, crop distribution, channel lining and other factors, and studies its improvement measurement. The results indicate that in hilly areas, rice planting and water leakage from low level channels are the major factors of water loss in irrigated areas, which provide important basis for water use efficiency and water-saving scheme in irrigated areas.