The offshore anti-rolling crane has the anti-rolling device consisting of four connecting rods with a rotating joint at the end of crane arm. Under the control of the motion control system, the anti-rolling device can compensate for the spatial displacement of the crane's lifting point caused by swinging, thereby reducing the rolling of the load. In order to calculate the spatial displacement of the lifting point before and after the swing, this paper establishes the kinematic model of the crane arm and the anti-rolling device. Since running in swing condition, the motion control system faces several challenges, such as load sudden change, the given signal time-varying, external signal interference. In order to improve the control performance, this paper builds the simulation model of servo motor control system of the anti-rolling device applying Fuzzy-PID control in MATLAB/Simulink. The simulation results show that the Fuzzy-PID control is more suitable for the motion control system of the offshore anti-rolling crane in swing environment, which significantly improves the control performance, such as stability, following ability and robustness.