In order to improve the success rate of salvage and safety of lifting process in high sea conditions, a method of flexible net salvage system was introduced, and a kind of active and passive composite wave compensation scheme was presented. The fuzzy adaptive PID algorithm was used to control the displacement of hydraulic cylinder, and to suppress the influence of ship rolling on the crane arm. According to the similarity criterion, the model of the salvage system was designed and the scale compensation model of the wave compensation system was established. The hydraulic swing platform was used to simulate the ship roll angle, the wave compensation effect of the prototype was predicted by testing the response time, the motion smoothness and the compensation accuracy of the scale model. The experimental results show that the system is stable and reliable; under the condition of 15° sine swing motion of the swing platform, the wave compensation motion error of the crane boom is maintained within ± 1°. The method theory and test data of the scale model can provide reference for the design of prototype.