Autonomous measurement device and method for geothermal well

The invention discloses a geothermal well autonomous measuring device. The device comprises a data cabin, a buoyancy adjusting cabin and a buoyancy providing cabin which are connected in sequence, wherein a pressure sensor and a speed and temperature sensor are arranged outside the data cabin, and a circuit module support, a data acquisition module, a data storage module and a power module are arranged inside the data cabin; an outer wall of the buoyancy adjusting cabin is composed of a filter screen, a water-soluble film and a water-soluble mixture which are sequentially arranged from outside to inside, and a rudder and a recovery module are arranged at the tail of the buoyancy providing cabin; an indicating lamp and a magnet recoverer are arranged in the recovery module; a data cabin cover is arranged on the side, close to the buoyancy adjusting cabin, of the data cabin, a sealing ring is arranged between the data cabin cover and the buoyancy adjusting cabin, the data cabin cover is fixedly connected with t