The manufacturing of curved section is a critical process with high difficulty in shipbuilding. It has realized numerical control over cold bending of section steel of curved section, but the outside plating of curved section is still processed by manual in almost all shipyards no matter at home or abroad. Because of its low productivity, poor working conditions, high labor intensity and the product quality that cannot be guaranteed and etc., the processing of outside plating becomes the bottleneck for shipbuilding. So, to realize the automatic processing of outside plating is the key point in improving the curved section manufacturing technique.