The effect of the compound system of IAEC?1306H (Isotridecyl alcohol polyoxyethylene ether carboxylic acid solution), alcohol solution and alkali agent on the viscosity of heavy oil was studied. The results show that under the same mass fraction conditions, maltitol has better viscosity?reducing effect on heavy oil than sorbitol, and NH₃·H₂O water has better viscosity?reducing effect on heavy oil than IAEC?1306H and alcohol solution.The mmonia water and IAEC?1306H have similar on the viscosity reduction effect of on heavy oil.With the increase of the volume fraction of NH₃·H₂O and the mass fraction of IAEC?1306H, the viscosity of the heavy oil gradually stabilizes.In the binary compound system, the binary system formed by compounding sorbitol and maltitol with IAEC?1306H respectively has the same viscosity reducing effect on heavy oil. And due to the nature of the alkali agent, the compounding of the alkali agent and IAEC?1306H is more conducive to the viscosity reduction of heavy oil.In the ternary compound system, the ternary system formed by the combination of NH₃·H₂O, maltitol and IAEC?1306H has a better viscosity?reducing effect on heavy oil, with a viscosity?reducing rate of more than 96%, and the dosage of NH₃·H₂O, IAEC?1306H, and maltitol are used less.