Tianjin is one of the early areas of large- scale development of deep geothermal reservoirs in China. After more than 30 years of continuous exploitation and recharge, whether there is any impact on deep geothermal reservoirs and whether it has caused environmental problems such as resource depletion, water quality deterioration and temperature decrease of geothermal reservoirs has been the focus of social concern. In this paper, the dynamic characteristics of different geothermal reservoirs in different areas of Tianjin were analyzed through vertical and horizontal comparisons based on the systematic collection of time series monitoring data of hot water utilization, reinjection volume, water level, water quality and water temperature for nearly 30 years since 1992 in different geothermal reservoirs in Tianjin. The results show that the main chemical components of geothermal fluids in geothermal reservoirs throughout Tianjin are basically stable and have not changed significantly over the years, and reinjection in the geothermal pumping and reinjection system will not fundamentally change the original chemical characteristics of the geothermal fluids, but the leakage recharge caused by deep large fractures as heat flow channels will have some impact on the water quality of the upper geothermal reservoirs. With the increasing recharge efforts in Tianjin in recent years, the continuous decreasing trend of water level in most geothermal reservoirs has been slowed down or rebounded, and the temperature of geothermal storage has no obvious trend of increasing or decreasing, but the target layer of reinjection wells cannot reach the initial temperature after the recovery of non- heating period, and it is decreasing year by year. Under the future continuous pumping and reinjection conditions, the “cold accumulation” of reinjection wells and the optimal deployment of pumping and reinjection wells should be a key concern.