Abstract: A large amount of low-temperature resources are exposed on the fracture zone at the northern edge of the Laji Mountain, with the water temperature below 25℃. Investigations of geothermal exploration holes of different depths that have been constructed in the area have ended in water without heat or heat without water, etc. The purpose of this paper is to fill the knowledge gap on the genetic makeup of geothermal resources in the region and to provide guidance on the future growth and use of these resources, this paper selects a typical geothermal system along the northern margin of the Lajishan fault zone as the research subject. Through in-depth analysis of the chemical characteristics and differences in the composition of hydrogen and oxygen isotopes of the geothermal waters of the nine groups, the genesis mechanism of the hydrothermal activity of the hot springs in the fracture zone was explored. The chemical types of geothermal water in this area are mainly characterized by HCO₃-Ca•Mg, HCO₃•SO₄-Na•Ca, Cl-Na type, Stored in relatively reducing environments with good closure, geothermal water is primarily recharged by atmospheric precipitation from the southern bedrock mountainous areas, with recharge altitudes ranging from 2515 to 4345 meters. The temperature range of the deep heat reservoir is between 38.3 and 82.5°C, and the circulation depth of the heat reservoir is between 746 and 2490 meters, with a mixing ratio of cold water ranging from 59% to 81%. The geothermal genesis in the area is thus established.. The geothermal genesis in the area can be divided into two types: deep circulation fault type and faulted basin type geothermal systems. This research provides certain data support for the rational development and utilization of geothermal resources..