The emulsion compounding technique facilitates the film formation of emulsions with high glass transition temperatures (Tg) at low temperatures and effectively avoids the problems of low hardness, poor adhesion and scratch resistance after film formation of conventional emulsions. In this paper, a series of phenylpropylene emulsions with different degrees of softness and hardness and different particle sizes were prepared by adjusting the proportion of soft and hard monomers, the amount of emulsifier and the synthesis process, using styrene (St), butyl acrylate (BA), acrylic acid (AA) and ectohexyl acrylate (EHA) as monomers. Through the tests of infrared, viscosity, particle size, surface morphology, water absorption, contact angle and mechanical properties, the effects of different hard phase ratios and different particle size ratios on the basic properties of the blended emulsions, films and coatings were investigated, and the emulsion models of the blended systems with different particle size ratios were constructed. The results show that there are obvious differences between the properties of conventional emulsions and compounded emulsions, and the emulsions after compounding have smaller particle sizes, a more stable system, and a significant decrease in the water absorption rate of the adhesive film. In the compounded emulsion, when the proportion of hard phase increased from 30% to 60%, the water absorption of the emulsion film decreased from 3.95% to 2.65%, the contact angle increased from 75.45° to 104.15°, and the tensile strength of the film increased in a gradient with the increase of the proportion of hard phase, but the film became brittle when the proportion of hard phase exceeded 60%. The larger the particle size ratio of the compounded emulsion, the more difficult the blended emulsion is to form a film at room temperature, and the water resistance and mechanical properties of the blended film were better with Ms:Mh=50:50 (soft and hard phase ratio). When the emulsions were applied to waterborne coatings, the gloss of the film could reach up to 81.4° when the ratio of hard phase was 30%, the impact resistance could reach up to 100 cm, the hardness of the film could be increased from B to H when the ratio of hard phase was increased from 30% to 50%, and the comprehensive performance of the film with Ms:Mh=50:50 emulsion was better.