The sealing problem of horizontal heavy duty cylinders has always been a difficult part of component design. The heavy-duty servo cylinder on the full hydraulic hobbing shear needs horizontal hinge installation, which outputs accurate curve displacement for the hobbing shear. This will cause damaged sealing structure, cylinder scuffing, oil leakage and other problems, resulting in insufficient output force. Aimed at the sealing problem of the horizontal heavy-duty cylinder, this paper added a new structure supporting the small cylinder at the bottom end of the servo-cylinder of the full hydraulic rolling shear, along with a control system, to balance the real-time dynamic self-weight. The friction between the end cover guide sleeve and the piston rod was an important control force of this design. By establishing a dynamic model, ADAMS and SIMULINK were used for co-simulation and bench test to compare and analyze the frictional forces before and after supporting the small cylinder. The results show that the friction between the guide sleeve and the piston rod was reduced rapidly after supporting the small cylinder. The feasibility of the system was verified by joint simulation and experiment, and the overall efficiency of the rolling shear was greatly improved.