In order to realize the roller detachability for the cross wedge rolling mill and facilitate the die replacement and heating, the roller end of the cross wedge rolling mill was designed, and the roller was fixed during operation and disassembled during die replacement which was realized by introducing a hydraulic system. Firstly, in order to further get the magnitude of force during the operation of  rollers, the axial load of the die during operation was obtained by simulation analysis, and based on this, a hydraulic locking circuit composed of hydraulic cylinders was designed. When the hydraulic cylinder was not working, the relative position between roller and cross wedge rolling half shaft was not changed due to factors such as leakage and axial impact, ensuring the stability during the cross wedge rolling operation. Secondly, in order to maintain the stability of the hydraulic system under the impact load, the hydraulic system mainly composed of hydraulic cylinders and dual hydraulic control check valve was designed, and optimization analysis was conducted based on its working state under working load. Finally, the hydraulic system was tested by the cross wedge rolling  mill prototype, which verified the feasibility of the system optimization scheme, improved the reliability and stability of the system, saved the time on die replacement, and accelerating the production efficiency of the enterprise.