The invention discloses a method and a device for judging a single-well water invasion situation of a water-carrying gas reservoir and controlling gas well production. The method for judging the single-well water invasion situation of the water-carrying gas reservoir comprises the steps of taking Gp(Ppi-Pp) / (Ppi-Ppwf) as x coordinates, taking q /
delta Pp as y coordinates, and drawing a first diagnostic curve; taking Gp as the x coordinates, taking Pwf / Z as the y coordinates, and drawing a second diagnostic curve; taking tca as the x coordinates, taking q /
delta Pp as the y coordinates, and drawing a third diagnostic curve; respectively carrying out gas well water invasion judgment on the first diagnostic curve, the second diagnostic curve and the third diagnostic curve; giving a gas well water invasion conclusion by integrating judging results, wherein Gp is the cumulative gas production in
current time, Ppi is a pseudopressure form of initial pressure of a gas well, Pp is the average pseudopressure of an oil reservoir in the
current time, Ppwf is a pseudopressure form of BHFP (Bottom Hole Flowing Pressure) of the gas well, q is the daily gas production of the gas well,
delta Pp is equal to Ppi-Ppwf, Pwf is the BHFP of the gas well, Z is a gas bias factor, and tca is a pseudotime function. According to the method and the device, disclosed by the invention, the reliability of judging the single-well water invasion situation of the water-carrying gas reservoir can be increased, and the production of the gas well can be reasonably controlled.