The research on rubble bed stability by ship stern flow is carried out using the physical model. The open-type rectangular pool of 14m long, 8m wide, and 1.2m high is chosen as a test pool, and uniform-sized stones are selected as the test bed rock. We use the submersible pump to simulate the tug propeller jet flow, and control the flow rate of the study area by adjusting different power submersible pump positions. The advanced Doppler-point current meter can measure the flow rate of the base bed riprap leading and trailing edge, and get flow rate indicators which can cause damage to the rubble bed stability. Practical engineering has verified the reliability of the research results.