The invention discloses a method for determining permissible application rate of sprinkler irrigation and belongs to the field of irrigation. According to the method, slope, slope top boundary length and slope length of a slope field are measured, the slope field is gridded according to the slope, the slope top boundary length and the slope length of the slope field, soil blocks contained by the slope field are obtained, a difference equation of each soil block is established, and the permissible application rate of sprinkler irrigation is obtained finally by solving the difference equation of each soil block. The surface detention-storage capacity is taken into consideration by the difference equations, so that the determined permissible application rate of sprinkler irrigation is relatively appropriate, soil is effectively irrigated, deeper waterlogging of the soil is avoided, and water resource is saved.