In order to improve the stability of Guantao and Gudao heavy oil，the improvement effect of dispersant NA1，AA，oleic acid，lauric acid and palmitic acid on asphaltene solubility was investigated，and the dispersant NA1 and AA were chosed due to the stable dispersion to the two asphaltenes. The effect of treatment temperature on the improvement effect of the dispersant and the interaction mode between the dispersant and the asphaltene were further investigated. It was found that the polyol nonionic dispersant NA1 could significantly increase the concentration of asphaltenes in the solution at low temperature；when the temperature was raised to 80°C，the concentration dropped sharply，which was still much higher than the asphaltene concentration without added NA1. The improvement effect of the sulfonic acid group-containing ionic dispersant AA was less affected by the treatment temperature. In addition，it was obtained by infrared spectroscopy that the sulfonic acid group of AA could form a red-shift hydrogen bond with the N—H bond and the O—H bond in the asphaltene. A functional group such as the hydroxyl group O—H，ether bond or ester group in NA1 could form a blue-shift hydrogen bond with the hetero atom such as N，O or S in the asphaltene molecule and the aromatic ring system conjugated π bond. Both dispersants interact with asphaltenes by adsorbing on the surface of asphaltene molecules and forming hydrogen bonds.