In a certain tight sandstone gas reservoir in Sichuan and Chongqing, gas and water are produced simultaneously, and the proportion of liquid-accumulating gas wells is high, which is generally low-yield and low-efficiency. The formation water of this gas reservoir has a high salinity and contains condensates, and most of them are large inclined wells. The production and recovery process is limited, with high costs and low efficiency. In response to these problems, we developed and improved the foaming agent suitable for the tight sandstone gas reservoir by studying the water production characteristics of the gas reservoir and the production characteristics of the gas well, through experimental tests of the foaming agent concentration, well inclination angle, temperature, salinity, and the comparative experiment of solid–liquid foaming and rowing. 42 gas wells were selected on the site for testing and implementation, and the test accuracy was above 90%. The average single-well daily increase in gas is 0.10,000 m3, the daily increase in water is about 5 m3, the production time rate is increased by about 30%, and the cumulative increase in gas is about 0.80 billion m3, accounting for about 15% of the total gas production. Foam drainage is one of the main technologies for drainage and gas production and has become the key technology for the efficient and stable production of gas and water-producing wells in this gas reservoir. The successful application in the tight sandstone gas reservoir realizes the effective resumption and increase in gas production of low-efficiency wells and flooded wells in Sichuan and Chongqing, has a wide application prospect, and also provides valuable experience and reference for the benefit tapping of other similar gas fields.