According to the principle of bladder power pump driven by ultrasonicvaporized steam, the urethral valve using rubber was designed, the structure parameter of urethral valve was determined. The mathematical models of driving force and urine flow rate of urethral valve were built based on the theories of ultrasonics and thermodynamics, and the effectiveness was verified by simulation and experiment. The 3D solid model of urethral valve was established and the opening size and shape of urethral valve under the different materials match and driving force direction was simulated using ANSYS Workbench. The effect of the opening size of urethral valve on urine flow rate was studied by experiment. The results show that the urethral valve can meet the functional requirements. The research findings can provide basis for the design and the study of urethral valve, which can also provide reference for the design of other implantable devices of human.