The invention discloses a method for developing geothermal energy through same-well recharging. A target geothermal reservoir is selected, and a water injection section and a water pumping section aredetermined; a vertical borehole is drilled, a sleeve is put downwards into a first opening section, then cement is injected for well cementation, drilling is conducted again, and a second opening section is subjected to barefoot well completion; a tail pipe is put downwards into a well till a packer on the upper portion of the tail pipe and a packer on the lower portion of the tail pipe are located between the water injection section and the water pumping section, an inner cavity of the tail pipe communicates with the water pumping section through a first sand-preventing screen pipe, the bottom of an inner cavity of the sleeve communicates with the water injection section, a submersible electric pump is connected to a bottom opening of a heat-preservation inner pipe, the heat-preservationinner pipe is put downwards into the well, and a water pumping channel and a water injection channel are sealed and spaced through an inner pipe sealing and fixing structure; and the top of the heat-preservation inner pipe communicates with a heat exchanger in a sealed mode, an outlet of the heat exchanger communicates with the water injection channel, high-temperature water is subjected to heatexchanging in the heat exchanger, and the water subjected to heat exchanging flows back to the water injection section. According to the method, the efficiency of single-well heating can be improved,and then economical and sustainable development of hydrothermal-type geothermal resources is achieved.