Abstract Using the SZW-1A digital thermometer, we survey the relationship of water temperature to depth and analyze short-term stability in Xin 11 Well, located in Hongyanchi, Xinjiang, China. We take the observational step as 10 meters, continue at one week for each point, take the average value as the water temperature, and compute the standard deviation of every point after the water temperature is stable. We determine the inflection point of gradient-depth is 400 m, the inflection point of stability-depth is 470 m, the interface of rocks is 380 m, and the borehole casing is 378 m. We conclude that, from the relationship of gradient-depth and stability-depth, the open borehole belongs to a weak permeability section and is inflected by low-temperature water, which comes from shallow circulating water.