To explore the deep down the tree down system under the condition of typical mechanical characteristics and influencing factors of the sensitivity of subsea tree down system based on independent improved mechanical model, carry out the deep down stage subsea tree down parameter sensitivity analysis of the process, to establish the working condition of mechanical characteristics of the tree down system. The results show that wave force and current force are the main factors in the deep water lowering stage. With the increase of velocity and wave height of surface current, the transverse displacement, stress and bending moment increase. The velocity of surface current caused the largest increase, followed by wave height; period and wind speed caused no obvious change. The horizontal displacement of the tree is too large in the deep water lowering stage, and the main reason for the docking failure is the sea current force. By converting the sea current velocity into the horizontal displacement, the maximum horizontal displacement is determined to be 2.7m.