A method is proposed to solve the problem of polishing the grooves and channels of matrix of Ring Laser Gyro(RLG). Both the glass-ceramic composition and chemical polishing mechanism are analyzed. Meanwhile, the technical solution, work flow and operation method are given. The result shows that the roughness and the transmittance of the surface, polished by the mixed solution of NH4HF2, H2O and additive, can reach 0.2～0.3 μm and 88～90% respectively. At the same time, the chemical polishing etching depth is 0~100 μm, realizing the "certainty" polishing to complex components.