Abstract: EPC contractor designs coating spraying system according to the coating system design in ISO 12944 The basic steps of design include the determination of corrosion environment, desired protection life (years) .type of coating material and thickness of coating.The quality control for key process is very important in the anticorrosion construction process.Firstly, the construction environment and surface preparation should be guaranteed to meet the needs of technical requirements, and the matching and formulating process for two-component coating material need to be well controlled;then, the spraying, curing and recoating assignments should be carried out according to environmental temperature and product performance:finally, the thickness control and final inspection of coating should strictly implement the related standards and ensure safe construction.If an economic, reasonable and simple-construction anticorrosion coating is designed according to the minimum allowable requirements in the tender documents, the qualified coating will be seen by the way of controlling the key procedures in spraying process based on appropriate construction technology.