In the paper, an aqueous emulsifying viscosity reducer was developed, which could improve low-temperature fluidity of Xinjiang crude oil. The effect of temperature, single and composite viscosity reducers on the viscosity of Xinjiang crude oil were investigated. The results showed that: the three single viscosity reducer, AEO、OP-10、AES, which had better viscosity reducing effect, were screened. At the same condition, the three viscosity reducer was arranged according to the viscosity reducing effect: AEO＞OP-10＞AES. Through orthogonal experiment, the optimum composition of composite viscosity reducer XJ-1 was obtained as follows: 0.3% AEO, 0.2% OP-10, 0.1%AES and 0.2% additive dosage NaOH. the viscosity of Xinjiang crude oil could be decreased to 40.56 mPa·s and the rate of viscosity reduction was above 98% through adding XJ-1 at 50℃ with the oil-water ratio?of 7: 3. At the same time, the emulsion had good stability and demulsifying and dewatering were much easier.