A method for reducing the viscosity of heavy oil

The present invention relates to a method for reducing the viscosity of heavy oil, comprising: adding a polyoxyethylene ethers and organotin carboxylate to the heavy oil, the reaction ≥4h at 80 ~ 200 ℃; ≥1000mPa 50 ℃ the viscosity of heavy oil · s, acid value ≥1.5mg? KOH / g; degree of polymerization of the polyoxyethylene ether is 5 to 30, in an amount of 0.05 to 3% by mass of heavy oil; the amount of the organotin carboxylate is 0.1 to 20% by mass of the polyoxyethylene ether. The method of the present invention can significantly reduce the viscosity of heavy oil.