In order to solve the problem of shape cutting hard brittle material disc parts, a shape cutting method based on electroplated diamond wire saw was proposed and the cutting experiment was carried out. The effects of cutting speed V(A), rotating speed n(B) of rotary table W axis and tension force F(C) of diamond wire saw on radial runout, wire bow angle, cutting efficiency and surface roughness of circular arc surface were studied systematically by using three factor and four level orthogonal test. The results show that the influence of W-axis speed on the radial runout (roundness), cutting efficiency and surface roughness of arc is the largest, followed by the tension force and the linear velocity. The influence of tension force on the wire bow angle is the largest, followed by the linear velocity and the W-axis speed is the smallest. In the range of the test conditions, the optimal combination of process parameters are A3B1C1, that is, the linear speed of diamond wire saw is 8.96 m/s, the rotating speed of rotary table is 0.25 r/h, and the tension force is 12 N. The range analysis results of radial runout, wire bow angle, cutting efficiency and surface roughness are consistent with their variance results.