According to the technical idea of surfactant depressurizing and increasing injection technology for injection wells in oil reservoir，the technology is studied for sewage water injection wells in gas reservoir to solve the production problems of increasing pressure and reducing capacity of water injection. By studying the compatibility between surfactant and water injection and the wettability reversal，the hybrid Gemini surfactant ZS-11 was selected，the phase permeability experiments and the depressurizing and increasing injection experiments was carried out. The results showed that ZS-11 had a good compatibility and strong wettability reversal ability at high temperature（130℃）and high salinity（80000 mg/L）formation condition，which made the core wettability changed from hydrophilic wetting to neutral wetting. Displacement experiments showed that the ZS-11solution with effective content of 0.2% could increase the relative permeability of liquid phase by 21.2%—52.8%，widened the gas-liquid two-phase permeability range by 9.3%，and decreased the saturation of equal permeability point by 3.3%—6.2% for cores with water permeability of 1.42× 10-3，1.78×10-3，5.27×10-3 and 10.53×10-3 μm2，respectively. Moreover，the effect of depressurizing and increasing injection was more obvious especially for low-permeability core，decreasing amplitude being up to 41%. The experimental results provide a new idea and method for solving the production problem of high sewage injection pressure in gas reservoir.