In recent years, geothermal resources have seen continuous development and utilization. With either single well recovery orrecovery by the well set ofa directional well connected with a vertical well, injected surface water and groundwater will exchange in the process of water injection exploitation of geothermal resources, resulting in the pollution of groundwater resources and a large number of environmental hazards brought by tail water since the well bore and the stratum are not completely isolated. It is specially true with the large scale development of geothermal resources in the city. Through the design and implementation of isolated heat exchange technology with connected geothermal wells, this paper analyzes the heat exchange efficiency of connected geothermal wells and the sealing measures between the well bore and the stratum to establish a set of isolated heat exchange and recovery methods, so that heat can be extracted without taking out ground water in the process of geothermal well recovery; thus providingbasic data and technical support for the development of geothermal resources around the city.