The invention provides a paint spraying circulating water treatment agent, a preparation method and a use method. The paint spraying circulating water treatment agent is prepared from an agent A, an agent B and an agent C, wherein the agent A is prepared from polyacrylic acid and ammonia water through a reaction; the agent B is prepared from amide polymers and water in a weight ratio being 1:(100-120), and molecular weight of the amide polymers is 18,000,000-30,000,000; the agent C is prepared from a compound Y and a compound Z through mixing, and a weight ratio of the compound Y to the compound Z is 1:1; the compound Y is prepared from polymeric aluminium and disodium ethylenediamine tetraacetate; the compound Z is prepared from sodium citrate and sodium pyrophosphate. The agent A, the agent B and the agent C can be prepared respectively and packaged independently, and the agent A is firstly added and uniformly stirred during using; then the agent B is added, and a mixture is stirred uniformly; finally, the agent C is added, the mixture is stirred uniformly, and a weight ratio of the agent A, the agent B and the agent C is 5:5:1. The paint spraying circulating water treatment agent is high in decaking capacity and paint is completely tack-free.