Abstract: Some of factories which have an effect on the freguency response of the hydraulic screwdown system are studied theoretically by the experimental investigation. This paper presents methods to increase frequency band, it includs flow compensation, double servo valve control, selecting the area of hydraulic cylinder properly, increasing the supply pressure of the oil source, using the servo valve with high rated flow and wide frequency band. A experimental setup is introduced, and the measurement of friction force for a large scale hydraulic cylinder and its measured results are first presented in published literatures. When the input signal to the control system is of 100 μ (p-p), the frequency band that　may be obtained for this experimental system is 13Hz, and the screwdown velocity has reached　4mm/s. The diameter of the hydraulic cylinder is 1000mm.