In order to study and determine the optimal compounding system that can improve the stability of heavy oil emulsion in Liaohe Oilfield and the law of emulsion stability under different conditions, a focused beam reflectometer(FBRM) and rheometer were used to pass four factors and three levels. Orthogonal experiment with three indexes explored the change law of droplet average particle size, dispersion degree and emulsion viscosity, and investigated the influence of external factors on the stability of emulsion under compound system. The results show that the compound emulsifiers with the mass fractions of OBS?50, AEO15/OS?15, OP?15, and sodium with mass fraction of 4.0%, 4.0%, 1.4% and 1.4%, respectively, are the most beneficial to improve Stability of heavy oil emulsion in Liaohe Oilfield; there is a positive synergy between average particle size and dispersion, and an inverse relationship with the viscosity of the emulsion; the increase in temperature, volume ratio of oil to water will weaken the stability of the emulsion; stirring rate, ore The increase of the degree of chemical conversion can improve the stability of the emulsion; when the mass fraction of the mineralized NaCl is 0.2% to 1.0%, the stability of the emulsion can be greatly improved, and the quality fraction of the emulsion can be further improved. The lifting effect is not obvious.