At present，the large-volume，high-rate acid stimulation technique is widely used for unconventional reservoirs. However，the challenges of rapidly preparing and continuously blending the acid solution have not been effectively resolved. In this paper，a cationic polymer emulsion was prepared by using acrylamide（AM），2-acrylamido-2-methylpropanesulfonic acid and N， N，N-trimethyl-dodecane-12-（ acryloyloxy ）ammonium chloride as raw materials. The structure of the polymer was analyzed by infrared spectrometer and nuclear magnetic resonance spectrometer，and a series of cationic emulsions were optimized. The swelling rate，constant temperature variable shear performance and static retardation performance of cationic emulsions were tested according to industry standards，the temperature resistance of cationic emulsions was tested by rheometer，moreover，the etching performance of cationic emulsion acid solution on rock was tested in combination with engineering parameters. The results showed that the viscosity of thickener acid solution at different cationic polymer emulsion dosage within 1 min could reach more than 90% of the viscosity after complete swelling. The viscosity of thickener acid solution with 4.0% cationic polymer emulsion could reach up to 123 mPa·s after complete swelling. The thickener acid had excellent shear sensitivity and shear recovery，which was beneficial for the thickener acid to maintain high viscosity and reach the formation smoothly under the influence of high-speed shear of the injection equipment. At the temperature of 120 ℃ and the shear rate of 170 s^-1 ，the viscosity of the thickener acid solution with 4% cationic polymer emulsion was about 52 mPa s after shearing for 120 min，and the retarding performance was more than 88%，which met the field requirements. The thickener acid could form non-uniform etching on the rock to ensure the conductivity after the transformation. The study indicated that cationic emulsions could meet the construction requirement of large-volume and high-rate operations.