Abstract: To estimate supercavity shape in supercavitating vehicle motion control, the pressure in inner and outside supercavity and the shape of supercavity were obtained in water tunnel experiments. Based on the collected data, the strong track filter (STF) was used to estimate the supercavity shape when cavitator rotated. The simulation results showed that the error between estimates and measurements of supercavity shape satisfied the requirements for stable motion control of supercavitating vehicles.