A flexible nozzle of the variable-rate sprinkler was developed. As the pressure increased, the diameter of the flexible nozzle increased and then the degree of fogging reduced. The main parameters of the nozzle, cone angle, range nozzle, length of end cylindrical section, thickness of elastic material, and extended volume of nozzle, were investigated. The 3-D solid model of the flexible variable nozzle and its internal runner were established using ANSYS software. The internal flow field of the flexible nozzle was simulated using computational fluid dynamics (CFD) software with k-ε model and ANSYS software with one-way fluid solid coupling model at different working pressure and different range nozzle. Relationship between working pressure, range nozzle and nozzle flow were evaluated. Simulation results were verified and precision of model was improved by measuring the displacement of the nozzle, the nozzle flow and the working pressure of the produced nozzle samples.