In order to improve the temperature and salt resistance of gas reservoir water intrusion inhibitors and mitigate secondary water intrusion contamination of gas reservoirs，methanol was used as dispersion medium. Through the measurement of surface tension，contact angle，spontaneous imbibition water saturation of cores，and gas-phase permeability in porous media，the surface activity，hydrophobic modification effects，and the ability to prevent and remove water invasion damage of five surfactants were studied. By measuring infrared spectrum，contact angle，Zeta potential and adsorption layer thickness，the mechanism by which the optimal gas reservoir water invasion inhibitor altered the wettability of gas reservoir water-wet sandstone surfaces was analyzed. The results showed that，among the five surfactants，the cationic fluorine-containing bicontinuous surfactant （HB-1） had strong hydrophobic modification ability as well as good high-temperature and high-salt resistance. After aging for 24 h at 180 ℃ and a salinity of 2.0×10⁵ mg/L，the surface tension of formation water could be lowered to 21.0 mN/m at a HB-1 concentration of 0.05%. After the core was treated with HB-1，the contact angle of formation water on the core surface increased from 45.0° before treatment to 110.0°. Injecting HB-1 into the porous medium could effectively prevent water invasion into the core，which could reduce the water saturation of core from 77.4% before treatment to 8.1%. It could effectively relieve the damage of water invasion， and then restore the gas-phase permeability of porous medium from 29.9×10^-3 μm² after water contamination to 52.3×10^-3 μm². The mechanism of HB-1 on the hydrophobic modification of water-wet sandstone surface was“adsorption”. HB-1 molecules could form a monolayer adsorption hydrophobic film with a thickness about 4.3 nm on the surface of water-wet quartz sheet. Furthermore，the thickness of adsorption film increased with increasing dosage of HB-1. When the mass fraction of HB-1 reached 0.1% ，the hydrophobic interaction between adsorption layers gradually formed a tightly oriented bilayer structure，and then the adsorption saturated. At this time，the Zeta potential was stable at 24.30 mV，and the thickness of adsorbed film was finally maintained at 4.3 nm.