The performance of hot-rolled steel plate coating film on the frame coating production line was studied,the properties of the film pretreatment process and the traditional phosphation process wer compared with the performance of the substrate integrated cathode electrophoresis coating,and the effects of different pretreatment methods on its neutral salt spray performance were compared.The results showed that the film pretreatment process could meet the technical requirements of the frame coating under certain pretreatment methods.