A power positioning method, used in a power positioning device to find a device location of a device to be measured in a space, the space comprising a plurality of known location devices, the method comprising the following steps: controlling the device to be measured to transmit a plurality of positioning signals by a plurality of transmission powers; causing the plurality of known location devices to receive the plurality of positioning signals, and recording a plurality of positioning signal intensities, a plurality of corresponding receiving times and coordinates of the plurality of known location devices to a database; finding out a plurality of known location devices with a larger signal intensity among the received plurality of positioning signals; querying a signal intensity-distance function and a signal intensity-distance standard deviation function from the database according to the plurality of positioning signal intensities, the plurality of corresponding receiving times and the known location devices with the larger signal intensity; grouping the plurality of known location devices according to different powers and setting the plurality of the known location devices as circle centers, using the signal intensity-distance function to obtain a distance, and using the standard deviation obtained by the signal intensity-distance standard deviation function to draw a plurality of circles; obtaining a plurality of intersections (a) between the plurality of circles; performing a triangulation process on the plurality of intersections (a) to obtain a plurality of triangles; and finding out a triangle with a smallest circumscribed circle radius among the plurality of triangles to set the center of the circumscribed circle to be the device location of the device to be measured. controlling the device to be measured to transmit a plurality of positioning signals by a plurality of transmission powers; causing the plurality of known location devices to receive the plurality of positioning signals, and recording a plurality of positioning signal intensities, a plurality of corresponding receiving times and coordinates of the plurality of known location devices to a database; finding out a plurality of known location devices with a larger signal intensity among the received plurality of positioning signals; querying a signal intensity-distance function and a signal intensity-distance standard deviation function from the database according to the plurality of positioning signal intensities, the plurality of corresponding receiving times and the known location devices with the larger signal intensity; grouping the plurality of known location devices according to different powers and setting the plurality of the known location devices as circle centers, using the signal intensity-distance function to obtain a distance, and using the standard deviation obtained by the signal intensity-distance standard deviation function to draw a plurality of circles; obtaining a plurality of intersections (a) between the plurality of circles; performing a triangulation process on the plurality of intersections (a) to obtain a plurality of triangles; and finding out a triangle with a smallest circumscribed circle radius among the plurality of triangles to set the center of the circumscribed circle to be the device location of the device to be measured.