The robot automatic spraying technology can effectively improve the spraying efficiency and spraying quality.But due to the particularity and complexity of product structure,the robot automatic spraying technology is seldom used in the large structural of crane.In this paper,the application of automatic spraying technology for large-scale structural parts is described from the aspects of the hanging and positioning determination,programming parameter setting,path planning,trajectory optimization and on-site spraying process optimization,and provided specific schemes for peer reference.