The invention discloses environmentally-friendly acrylic ester coating printing adhesive emulsion and a preparation method. An emulsion polymerization process is adopted. The emulsion comprises the following raw materials in part by weight: 50 to 90 parts of soft monomer, 10 to 20 parts of hard monomer, 2 to 10 parts of functional monomer, 2 to 5 parts of emulsifying agent, 0.2 to 0.5 part of initiator, 0.2 to 0.5 part of pH buffer, 80 to 120 parts of deionized water and a proper amount of pH adjustor, wherein the total amount of the soft monomer, the hard monomer and the functional monomer is 100 parts by weight. The three monomers are cooperatively used as functional monomers for generating carboxyl crosslinking, hydroxy crosslinking, epoxy crosslinking and the like so that the obtained printing adhesive emulsion has excellent water tolerance and mechanical property. The crosslinking monomers and the emulsifying agent do not contain the components such as N-methylol acrylamide, APEO and the like, so the emulsion does not release formaldehyde during baking and using and is suitable for high-grade environmentally-friendly printing adhesive.