Three-factor four-level orthogonal experiments were first conducted to study the influence of technical parameters on surface roughness of PCD tools during the cloth-wheel polishing process which removes thermal damage layer of PCD tools.The test results show that the roughness changing value increases at first and then decreases with the increase of rotation speed; the roughness change value increases at first and then decreases, and increases again as compression amount increases; the roughness changing value increases at first and then decreases with polishing time extending. In the following, the influence degree of cloth-wheel speed, compression amount and polishing time on the changing value of the roughness is analyzed, and a ternary-quadratic prediction model of roughness changing value is established.The results show that the rotation speed of cloth wheel has the greatest influence on roughness changing value, followed by the compression amount, and the polishing time is the smallest; the correlation between the rotation speed, compression amount, polishing time and the roughness changing value is significant, and the model of roughness changing value fits well with experimental data.