Based on Zwart-Gerber-Belamri cavitation model, a numerical calculation method of cavity flow of water-exit missile with complex configuration was proposed, in which the technology of dynamic mesh and composite mesh was used. Cavitation formation, evolvement and influence of shoulder, rudder and protuberance of water-exit missile were analyzed. The simulation results acclaim that in the beginning of water-exit course, body-attached bubble quickly grows due to reduction of cavitation number. After that, the effect of bubble break-off and oscillation becomes more obvious. The cavitation of shoulder firstly appears at the water-exit speed of 15 m/s. And it grows quickly with water-exit speed. The dissymmetry of shoulder cavitation becomes obvious in the attack angle of 5°～10°. The cavitation of rudder is hardly influenced by waterexit speed. The proportion of cavitation area of rudder is less than 10% when the attack angle is less than 5°, and rapidly increases to 50% when the attack angle beyond 5°. Reduction of protuberance size is beneficial to cavitation avoidance. The influence of the attack angle on protuberance cavitation is unapparent. Protuberance can induce the cavitation on nearby missile body at high speed.