The spherical joint has the characteristics of long span, high strength, light weight, beautiful shape and no support. However, due to the irregular shape of the spherical joint, it is difficult to carry out sandblasting and other surface treatment, and the coating is easy to flake here, which requires frequent follow-up maintenance; In the subsequent construction, the original coating and rust layer must be removed, the surface treatment is complicated, the later maintenance cost is high, and the protection effect is not ideal. The oxidation polymerization coating technology is used in the thermal power plant to cover the spherical joints with complex structure.