Abstract: The effects of retraction speed, retraction distance, extra restart distance and extruder temperature on drawing phenomenon and surface roughness of products was studied by orthogonal experimental design method. The influence level of process parameters on the surface roughness of samples is evaluated by analyzing range of the measured results, and obtain the optimal combination of process parameters. The significance test is further carried out by ANOVA. The results show that the influence degree of various process parameters on the surface roughness is in the order of size as follows: extra restart distance, extruder temperature, retraction distance, retraction speed, and the retraction distance has the strongest influence on drawing phenomenon. The optimal combination of process parameters as follows: retraction speed 50 mm/s, retraction distance 6 mm, extra restart distance -0.5 mm and extruder temperature 185 ℃.