In order to probe the effect of CO₂ on super heavy oil in CO₂ assisted steam huff and puff technology, physical properties of super heavy oil in Zheng 411 reservior under different amount of CO_{2 injection, different pressures and different tempretures were studied through gas injection swelling tests systematically, and predictive models for solution gas-oil ratio, bubble point pressure, oil viscosity, oil density and volume factor with CO2 content, pressure and temperature were established by means of multiple regression with high accuracy. The results showed that the solution gas oil ratio of the studied super heavy oil increased with the increase of the CO2 content linearly; the bubble point pressure increased with the increase of the CO2 content linearly, and increased with the increase of the temperature in a strong power relation; the oil viscosity decreased with the increase of the CO2 content exponentially, the natural logarithm of which decreased with the increase of temperature exponentially; the oil density decreased with the increase of the CO2 content exponentially, and decreased with the increase of temperature logarithmically, while increased with the increase of pressure linearly; the volume factor increased with the increase of the CO2 content exponentially, and increased with the increase of temperature exponentially, while decreased with the increase of pressure linearly. The viscosity of super heavy oil is very sensitive to temperature, and the oil mobility will be improved with the increase of temperature. Besides, dissolved CO2 can reduce the oil viscosity and swell the oil, which is helpful for the production of super heavy oil.}