In order to achieve automatic spraying of putty on the surface of rail vehicle bodies，a robot automatic spraying platform was built. The optimal process of automatic spraying was studied using orthogonal experimental method，and the putty construction parameters were investigated and determined. The advantages of automatic spraying putty andmanual operation were compared and analyzed. The results show that the process parameterssuitable for automatic spraying putty on rail vehicles are：putty viscosity 9 512 mPa·s，spraying pressure 420 MPa，spraying distance 500 mm，moving speed 600 mm/s，fan width 300 mm，and film thickness 2. 00 mm. The construction parameters of putty are：heating temperature of putty 80 ℃，maximum time between recoating 96 hours，maximum dry film thickness of single spray flow not exceeding 700 μ m，maximum film thickness without bubbles 2. 09 mm，self drying and polishing properties for 4 h，and easy polishing of 80-120 mesh sandpaper. Compared with manual operation，automatic spraying indicated good quality consistency，effectively reduces labor costs，improving efficiency，and significant economic benefits.