Spraying method for coating in valve set on oil field petroleum conveying pipeline

The invention relates to a spraying method for a coating in a valve set on an oil field petroleum conveying pipeline. The spraying method comprises the following steps of (1) carrying out carbonization on oil stains and impurities on all parts of the to-be-treated valve set; (2) carrying out surface treatment on the rest places, except a sealing surface, of the inner surface of the valve set, andremoving the carbonized oil stains and impurities; (3) spraying primer on the inner surface of the valve set, and carrying out preliminary solidifying by using a continuous furnace; (4) continuously spraying finish paint on the inner surface of the valve set; and (5) carrying out final solidifying by using the continuous furnace, namely finishing spraying. Compared with the prior art, the oil stains and the impurities attached to an inner wall of the valve set can be effectively removed, and meanwhile, the coating and a base material are tightly bitten together through two-layer coating with the primer and the finish