Abstract: Jiaohu karst lake is located in Hucun Basin of Ninghua County in Fujian Province. It is a special type of karst landform, and the formation of karst lakes is closely related to its climatic conditions, hydrological conditions and geological history. The geological genesis of Jiaohu karst lake is an important basis for studying the tectonic uplift and the development and evolution of underground water systems in karst areas of the northwest Fujian Province. Through analyzing the geological background and karst development characteristics, the authors adopted a comprehensive geophysical exploration method based on high-density electrical method and multibeam bathymetry system for unmanned vessels. The tectonic development location, spatial morphological characteristics and depth information of hidden karst were detected by high-density electrical method. The distribution and extension of water flowing channel in Jiaohu karst lake were detected and two hidden karst groundwater run-off bands were presumed. The underwater terrain data was obtained by scanning the multibeam bathymetry system for unmanned vessels, and the underwater three-dimensional morphological model of the karst lake was constructed. The shape and position of two infundibula form channels in the karst lake were detected to realize the accurate tracking and positioning of the water flowing channels. The trend of two concealed karst groundwater runoff zones in the study area and their relationship with Jiao karst lake were identified, and the water supply channel and supply source of Jiao Lake were analyzed, indicating that the karst area of Jiao lake had close connection with groundwater system and the karst channels were complex. With the intermittent tectonic uplifting since Pleistocene, the groundwater system flowed to the deep, resulting in the reducing erosion base level. This would further cause karst collapse formed by the erosion of groundwater seepage. The deep water flowing channels were connected with underground water, which was a special karst lake formed by water-creep and gravitational-collapse mechanism. The research achievements about the infuencing factors of Jiaohu's formation and its geological genetic mechanism could provide scientific basis for the protection and utilization of special karst landscape resources.