Abstract: The processing efficiency of the hemispherical shell resonator (HSR) is the main factor affecting the application of the hemispherical resonator gyroscope (HRG). Based on the annular magnetorheological finishing method, a simplified planar toroidal polishing head was adopted to estimate its machining performance. The effect of several factors on polishing performance was explored through single factor test and orthogonal test, namely magnetic field intensity, polishing head rotation speed, gap between workpiece and polishing head, and abrasive size. Results show that when polishing fused quartz glass at strong magnetic field intensity, polishing head rotation speed of 350 r/min, gap of 0.6 mm, and diamond size of 0.5 to 1.0 μm, the material removal rate reaches 191.2 nm/min and the average surface roughness R_a is 3.31 nm, thus exhibiting excellent processing properties.