Various links such as marking,part cleaning,gluing,assembly,and repainting during assembly were reviewed,and common problems affecting the quality of the surface paint film of the product were pointed out,which could lead to poor environmental resistance and appearance quality of the overall paint film of the product after subsequent topcoat spraying.Three control measures have been proposed to strengthen quality awareness,establish systems to improve processes,and strengthen supervision to ensure the quality of the surface paint film of the parts in various stages of assembly.