The action recycle of micron wood fiber filter molding machines hydraulic system was introduced. Cosimulation was conducted by AMESim and MATLAB/Simulink according to the principle of hydraulic system. And the molding machines control performance was improved greatly by using fuzzy PID control algorithm. The results show that the length error of micron wood fiber filter between each other, which produced after optimization of the hydraulic modeling system, is controlled within 1 mm, which meets production requirement.