The invention relates to an aqueous primer used for bicycles, which comprises the following components in percentage by weight: 25-45% of aqueous 
epoxy acrylate resin, 2-10% of curing agent resin, 1-3% of neutralizing agent 
dimethylethanolamine, 2-10% of compound anticorrosive 
pigment, 5-20% of tinting 
pigment and filler, 0.1-0.5% of antifoaming agent, 0.1-0.5% of flatting agent and 20-40% of deionized water, wherein the sum of the content of all components is 100%. The aqueous 
epoxy acrylate resin accounts for 10-40% of the total 
mass of 
epoxy resin; the curing agent resin comprises aqueous closed-type 
polyurethane curing agent resin and amino curing agent resin, wherein the 
mass ratio of the aqueous closed-type 
polyurethane curing agent resin to the amino curing agent resin is 1:5-5:1; the aqueous closed-type 
polyurethane curing agent resin is decapsulated and solidified at the temperature of 130DEG C; the amino curing agent resin is carbinol or butylated amino 
melamine formaldehyderesin; and the compound anticorrosive 
pigment comprises modified 
zinc phosphate, 
zinc oxide and 
ion exchange type anticorrosive pigment. The aqueous primer disclosed by the invention is especially suitable for preventing 
rust and 
corrosion of structures, such as bicycles and the like.