The power station power part looseness positioning system which comprises a pressure vessel and also comprises a first acceleration sensor, a second acceleration sensor and a third acceleration sensor which are arranged at the top of the pressure vessel. The first acceleration sensor is connected to a first preamplifier. The second acceleration sensor is connected to a second preamplifier. The third acceleration sensor is connected to a third preamplifier. The first preamplifier, the second preamplifier and the third preamplifier are connected to a signal conditioner which is connected to an industrial personal computer through an IN data collection system. A power station power part looseness positioning method comprises the steps of (1) detecting the looseness signal of an off component, (2) filtering, (3) carrying out signal analysis and signal collection, and (4) carrying out arithmetic processing by the industrial personal computer to obtain a result.