Coating particles of automotive topcoats were analyzed and summarized,and the main sources of topcoat coating particles were paint residue,varnish residue and grinding dust.The production site measures were adopted such as adjusting the air balance of the spray booth,strengthening the cleaning of spraying equipment and tooling tools,sealing the open area before spraying,and standardizing standard operating procedures to improve paint particle problem.According to statistics,the number of top paint particles on a single table has dropped by 64%,improved the appearance quality of painting and the efficiency of production line.