A fluorinated polystyrene-acrylate emulsion (BSAD) was prepared by soap-free emulsion polymerization from dodecafluoroheptyl methacrylate (DFMA), butyl acrylate(BA)、styrene(ST) and acrylic acid(AA), with (NH4)2S2O8(APS) as an initiator. And the chemical structure, morphology of latex grain，size distribution and Zeta potential of BSLD were characterized by Infrared spectrum (IR) ,Transition electron microscopy (TEM), particle analyzer and Zeta potential analyzer. The effects of temperature and dosages of sodium acrylate、APS and DFMA on properties of emulsion were discussed. And the emulsion was employed with nano-TiO2 to prepare the fluorocarbon coating. The results showed that: when dosage of sodium acrylate was 12%, APS was 1%, and reaction temperature was 78℃,the emulsion displayed the best properties and its gel rate was 0.8%, time of water tolerance was longer than 168 hours, percent conversion was 97.1%; when dosages of DFMA was 25% of monomers ,the coating displays the best hydrophobicity and water contact angle on its surface was 113°, water absorption rate was 6.4%; and the fluorocarbon coating won satisfied effect about its properties such as the adhesion, hardness and water resistance.