In view of the high viscosity and poor fluidity of super heavy oil and high salinity of formation water，emulsified viscosity reducer was prepared by surfactant，alkali and organic phosphoric acid and its formula was optimized. The effects of salinity and temperature on the viscosity-reducing properties of viscosity reducer were studied and the mechanism of viscosity reduction was analyzed. The results showed that the optimal formula of emulsifying viscosity reducer for super heavy oil was obtained as follows：1.1∶0.45∶1.15 the mass ratio of compound surfactant consisting of sulfonate anionic surfactant YBH and alcohol ether carboxylate anionic-nonionic surfactant YFBH with a mass ratio of 1∶1，alkali and salt resistant additive NYZJ-1. When the dosage of compound agent and additives was 0.81% in the emulsion，emulsification temperature was 80℃，the mass ratio of oil to water was 7∶3 and the salinity was 95 g/L，the viscosity of super heavy oil reduced from 316.5 Pa·s to 0.0831 Pa·s at 50℃，the viscosity reduction rate was up to 99.97% and the water separating proportion was only 5.93% after standing in 4 hours at 50℃. Temperature had little effect on the viscosity-reducing property of viscosity reducer and the viscosity reduction rate of super heavy oil emulsion remained unchanged after 2 hours treatment at 200℃ . The synergetic effect among the components of the compound emulsifier enhanced the viscosity-reducing property of the system and the stability of emulsion. The emulsified viscosity reducer had good viscosity-reducing effect and could withstand temperature and salt，which was suitable for the oil reservoir with high temperature and high salt.