Abstract: In order to study the influence of turning parameters on the surface roughness of A100 steel, the orthogonal turning test of A100 steel was carried out with cemented carbide tools. The influence rule and significance degree of turning parameters on the surface roughness were analyzed, and a multivariate linear regression model of the surface roughness was established. The results show that the surface roughness increases with the increase of feed rate and cutting depth, and decreases with the increase of spindle speed. The primary and secondary order of the influence of turning parameters on the surface roughness is f > a_p > n, and the accuracy of the regression model is verified by the significance analysis of the regression model.