Abstract: Turning tests were conducted on TC18 titanium alloy by orthogonal testing method. The effects of spindle speed, feed depth and cutting depth on cutting force and surface roughness were studied by intiutive analysis, empirical model analysis and range analysis. The results show that compared with feed depth and spindle speed, the effect of cutting depth on cutting force was the largest. The cutting force increased with the increase of cutting depth. The effect of feed depth on surface roughness was the largest, the effect of cutting depth was the second, and the effect of spindle speed was the least. In the exponential empirical model of cutting force and surface roughness, the model with higher fitting degree was the parameter model of main cutting force (F_z), and the significant degree was relatively high.