Abstract: The cavitation of a high-speed moving body in water would change the surrounding flow field structure, which affect the speed measurement turbine. It is of great significance to study cavitation characteristics of the speed measurement turbine to improve autonomous environment perception ability of a moving body. Based on the cavitation structure design of the inner speed measurement turbine, cavitation morphology and dynamic characteristics of the turbine speed measurement device were studied by using cavitation water tunnel experiments and numerical simulation methods for different cavitation numbers and flow angles at a water flow velocity of 10 m/s. According to the results of simulation and experiment, the characteristics of each stage of cavitation development are analyzed and compared. The results show that: compared with the prototype without turbine, the cavitation area has changed significantly, the shedding of cloud-like cavitation mass shedding is significantly accelerated, and the cloud-like shedding range is smaller. At the same time, the turbine could isolate external cavitation. When the external cavitation number is higher than the critical cavitation number (σ_Cr=0.4), the turbine can be used properly within the linear measurement range.