Abstract: Physical simulation experiments have been conducted by injection of high-temperature gas mixture because the oil field development results are very poor with conventional water flooding method in Zhaoyuan Oilfield. Using the basic tube-type physical simulation device, laboratory gas injection or gas-water mixture injection experiment was conducted and the results were compared by using different gas steam ratio, different slug of injected gas, and different injection temperature and formation temperature. The results showed that the oil displacement efficiency increased when increasing the temperature of the mixed gas, and oil displacement effect is the best when injecting flue gas-water slug with 1:1 fuel gas-steam ratio.