In order to overcome the shortcomings of polyacrylamide power chemicals, two kinds of emulsion polymers P(AM/KAA/C4A) and P(AM/KAA/C6A) were synthesized by emulsion polymerization with acrylamide, acrylic acid, dimethylaminoethyl methacrylate, 1-bromobutane or 1-bromine hexane as raw materials. Laboratory experiment results showed that the performance of two polymers was quite similar. The dissolution time of homemade emulsion polymer was less than 5 min. It was more suitable to use P(AM/KAA/C4A) as additional agent due to the less cost than P(AM/KAA/C6A). After adding 0.6% P(AM/KAA/C4A) to the fresh water mud, the value of apparent viscosity (AV), plastic viscosity (PV), yield point (YP) and filtration quantity (FL) was 30.5 mPa·s, 18.5 mPa·s,12.0 Pa and 12.2 mL. After ageing 16 h on the condition of 150℃, the value of AV, PV, YP and FL was 25.5 mPa·s, 17.0 mPa·s, 8.5 Pa and 14.2 mL, respectively. The mud could resist saturated salt solution after adding 0.6% P(AM/KAA/C4A). The contrast experiment result showed that the performance in temperature and salt tolerance of homemade emulsion polymer was better than that of Daqing and Hebei emulsion polymers. When 0.6% homemade emulsion polymer was added to the compound salt mud, the value of AV, PV and FL was 14.0 mPa·s, 8.0 mPa·s and 43 mL after aging 16 h at 150℃, which showed that the homemade emulsion polymers could be used as a drilling fluid additive.