The expansion and transformation of the original line body of the electrophoresis line in the paint shop is a difficult point in construction. The original factory capacity design cycle time is 3 4 JPH, in order to meet the market demand and the cycle time has been increased to 50JPH. It is required that the electrophoretic wire transformation should be completed under the premise of "non-stop" within 4 months from project approval to construction. It was completed under the premise of "pre-process/project management planning, identification of critical paths for transformation, and construction technology innovation to achieve "non-stop" construction of the electrophoresis line, and finally the production improvement without affecting production was realized.