Abstract: Taking the betaine of molecular structure containing sulfonic acid groups and longer main carbon chain as the main component, compounded with a small amount of straight chain paraffin sulphonate having synergistic active effect, a high temperature foaming agent was developed. The foaming agent can significantly reduce the surface tension and interfacial tension of the formation water, and has good surface activity being favor of foaming. The foamability, foam stability and carrying liquid ability of foaming agent are all preferable, it has good thermal stability at 150 ℃, and shows a strong resistance ability to high temperature. The lab simulation experiment device with high temperature gas well foaming agent for drainage can simulate high temperature gas well foam drainage process factually. The experiment evaluated the foam dynamic performance of foaming agent at 150℃. The simulation results show that the foaming agent still has good liquid carrying capacity at 150℃.