Anionic emulsifier and nonionic emulsifier were used as the complex emulsifier.The levels of emulsifier under 3%,the waterborne coating acrylate microemulsion with the solidscontent up to 43.7% was developed,by the technology of preemulsificationon and seed emulsion polymerization.The parameters of polymerization technology were optimized by the orthogonal experiment.The structure and the properties of the polymer were charaterized by DSC,GPC,FT-IR and Lo-C.