A hydrodynamic suspension machining system based on NC machine tool is constructed. And a compliant machining apparatus was developed. Fluid pressure distribution in the machining clearance was analyzed by hydrodynamics. The experiments to find influence on fluid pressure of machining clearance and motor rotate speed. Meanwhile

by conducting experiments

the correlation between the surface roughness of machining clearance and motor rotate speed was revealed. Experimental results indicate that with the increasing of motor rotate speed and decreasing of machining clearance

fluid pressure increased gradually and then decrease relatively after it reached certain value. When the motor rotate speed is 6000 r/min

the hydrodynamic pressure obtained max value. It was shown that when the machining clearance is between 5 and 40 m

the machining effect is distinct. And in the condition of maintaining clearance 10 m and hydrodynamic pressure maintained to be 5N

the machining effect is optimal.