Abstract: The present invention provides a system for supplying heat by means of stratum coal in-place slurrying and a method for supplying power generation heat by means of stratum coal in-place slurrying, belonging to the technical field of ground-source well heat exchange. The system comprises a stratum coal slurrying device, a mid-deep well casing device and a heat exchange device. The stratum coal slurrying device comprises a water inlet pump and a coal slurry pump, which are connected to a directional slurry preparing drill through pipelines, respectively. The mid-deep well casing device comprises a vertically buried pipe, and a heat-insulating inner pipe that is coaxial with the vertically buried pipe and inserted into the vertically buried pipe. A microporous pipe assembly is arranged on the bottom of the heat-insulating inner pipe.