Abstract: An external turbine can be used to an underwater conventional weapon fuze to measure its own velocity. The study on turbine cavitation characteristics with high rotating speed is of a great significance to the measurement error analysis of the turbine speed and moving distance. Based on the mechanism of cavitation occurrence and development, numerical simulation and water tunnel experiment were performed to observe turbine cavitation shapes and cavitation dynamics under 10m/s and 8m/s water flow velocity in different cavitation numbers. The turbine rotation conditions under cavitation were also analyzed. According to the simulation and experiment results, the turbine cavitation characteristics of all development stages were analyzed and compared. The results show that the law of turbine cavitation development and the turbine cavitation dynamic characteristics can be predicted well by numerical methods. At a certain water flow velocity, the turbine rotational speed increase slightly at first and then decrease with decreasing cavitation number. At some flow velocity and cavitation number, there is a significant low-frequency periodic variation in turbine rotating speed signals.