In prototype stage ,many mechanical products have to go through all kinds of static loading test, and vibration test. Many vibration test bench are hydraulic driven. Cylinder on test bench require high frequency and low friction characteristics. Low friction on one hand can reduce heat and prolong the service life of the seals, on the other hand can increase position control accuracy. High-strength material and optimized structure design improve the fatigue strength of the cylinder itself greatly. The seals and support on rod and piston are special designed that can achieve a extremely low friction. We also have rich experience in control block design for high frequency cylinders.