The invention discloses an agglutinant of paint spray mist and a preparation method and application thereof. The agglutinant of paint spray mist comprises a component A and a component B, wherein the volume ratio of the component A to the component B is 1:3-3:1; the component A refers to a melamino-formaldehyde resin co-modified with urea and a phenol compound in a natural material; and the component B comprises the following components in parts by weight: 90-110 parts of a polymeric flocculant, 20-30 parts of water soluble silicate, 10-20 parts of poly aluminum chloride and 5-8 parts of dodecyl primary amine hydrochloride. The polyacrylamide with high molecular weight and modified lignin are taken as flocculating agents, the flocculating effect is improved, and the modified lignin has good dispersing performance and has significant effects of improving the slag forming efficiency and increasing the paint slag removal speed. The agglutinant of paint spray mist prepared by the invention has the advantages of low formaldehyde content, obvious debonding effect, good flocculating effect, high slag forming efficiency and high paint slag removal rate.