The invention discloses a waterborne 
rust conversion 
polymer emulsion. The waterborne 
rust conversion 
polymer emulsion is prepared by the polyreaction of alkenyl 
halide monomers, monomers of (methyl)
acrylic acid and esters of (methyl)
acrylic acid, 
alkene phosphate ester monomers, a complexing agent, a compound emulsifying agent, an initiator and deionized water in an 
inert atmosphere at a pressure of 0.08 to 0.12MPa and a temperature of between 50 and 60 DEG C; and the percentages of dosages of all components on the basis of the total weight of all polyreaction monomers are: 75.0 to 95.0 percent of alkenyl 
halide monomers, 1.0 to 5.0 percent of 
alkene phosphate ester monomers, 5.0 to 10.0 percent of monomers of (methyl)
acrylic acid and esters of (methyl)acrylic acid, 0.05 to 0.5 percent of initiator, 2 to 4 percent of compound emulsifying agent, 1.0 to 10.0 percent of complexing agent and 100 to 120 percent of deionized water. The 
coating prepared by the 
emulsion has the characteristics of good 
adhesive force, strong covering force, good stability, 
acid resistance, alkali resistance, salt spray 
corrosion resistance and long service life, and can be directly coated on the surfaces of 
metallic materials with a tight rusty layer without the 
rust removal treatment; and in a film-forming process, no volatile organic compounds are discharged, so that the 
coating of the invention is a green environmentally protected antirust 
coating.