Polymer emulsifier was prepared using methyl methacrylate (MMA), butyl acrylate (BA) and 2-hydroxyethyl acrylate (HEA) as monomers, azodiisobutyronitrile (AIBN) as initiator. The influence of amount of HEA on water-solubility of polymer emulsifier, the relationship between T-g of polymer emulsifier and T-g of waterborne varnish, and the effect of polymer emulsifier amount on the properties of waterborne varnish such as particle size, viscosity, gloss value and water absorption were investigated. The results showed that while the amount of HEA is 30%, the water-solubility of polymer emulsifier is perfect. When the T-g of polymer emulsifier is similar to that of the waterborne varnish and the polymer emulsifier concentration is 2%, waterborne varnish is smaller particles, viscosity moderate, better water resistance and higher gloss degree.