Abstract: A new control method of hydraulic cylinder speed is put forward. It control the cylinder speed by discrete precise displacement. The perform institution of AMT (Automated mechanical transmission) vehicle’s clutch always adopts hydraulic cylinder. But its motion presented being subjected to many factors in reality, such as the change of oil’s viscosity and the restoring force of spring, etc. It brings difficulty to its control. The experiments show that the proposed method can make the clutch engage at any precise speed and has great ability of fault tolerance.