Polyurethane-epoxy-acrylate copolymers (PUEA) used as waterborne pressure-sensitive adhesives (PSA) were synthesized by a two-step copolymerization of acrylates with unsaturated double bound terminated polyurethane (PU) and epoxy resin. DSC and TEM analysis indicated that the modified copolymer was a homogeneous system and there was no phase-separation between the components. The effects of additions of PU and polymerization processes on PUEA emulsion properties and adhesion performances were also studied. The experimental results showed that the pressure sensitive performances and high temperature resistance of modified PUEA were greatly improved. When the content of PU was 6% , the properties of PUA emulsion were good. The stability, adhesion performance, and temperature resistance of the emulsions by chemical copolymerization were better than those of physical blending.