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Stabilizing crane plays an important role in the lifting of cargo between ships and offshore platforms, such as wind turbine and drilling platform under high sea conditions. According to the characteristics of motion compensation offshore, a parallelserial hybrid stabilizing crane mechanism was proposed. The parallel part is a two degrees of freedom (DOF) rotational parallel mechanism (RPM), which has two continuously rotational DOF. The parallel part, with a virtual continuous axis, can isolate the impact of the rolling and pitching of the moored ship to provide a stable base for the serial part: PRRP kinematic chain. The serial part has the degree of heave, yaw, tilt and telescope. The whole stabilizing crane can keep the end point of the crane staying still relative to the earth. Firstly, the hybrid mechanism was described and the corresponding coordinate systems were established. Then, assuming the parallel part and the first P kinematic pair of the serial part compensated the motion of the moored ship, in the non-inertial system, combined the vector method and screw velocity and acceleration theories, the kinematic model of end of the stable gangway stabilizing at a fixed point was established in accordance with the sequence of the parallel part and the serial part. Based on Newton-Euler formulas in screw form and combined D’Alembert principle and virtual work principle, the dynamic model of the hybrid mechanism was established in accordance with the sequence of the serial part and the parallel part. Finally, the correctness of the models was verified by a numerical example. The work laid a theoretical foundation for the engineering application of the stabilizing crane. 