The invention discloses a waterborne polyurethane acrylate emulsion and waterborne plastic ink prepared by the same. During an emulsifying process of polyurethane prepolymer, an amino chain extender is used to extend the chain and seal the end, then polyurethane prepolymer is reacted with isocyanate acrylate to introduce double bonds, and finally graft acrylate, thus preparing the waterborne polyurethane acrylate emulsion. The obtained waterborne polyurethane acrylate emulsion has large molecular weight of polyurethane segment, improves the mechanical property of waterborne polyurethane acrylate, has both the flexibility of polyurethane and the excellent adhesive force on PET and NY, and has both the good water resistance of polyacrylate and the adhesive fastness of PP; no emulsifier exists in the waterborne polyurethane acrylate emulsion, thus an excellent dispersion effect on pigments is obtained and the waterborne polyurethane acrylate emulsion can be used as grinding resin to prepare mill base. The waterborne polyurethane acrylate emulsion can be used for preparing waterborne plastic ink, the prepared waterborne plastic ink is non-toxic and odorless, good in resolubility, good in water resistance, has excellent adhesive force on substrates such as PP, PET and NY, has strong release force and can be applied to plastic packaging composite ink.