An acquiring and amplifying device of a passive AC micro-current comprises a multi-winding insulating coil, coil taps of N times of number of turns are extracted from the coil to be connected with device leading-out terminals respectively, and the device leading-out terminals comprise a common terminal 0, 1N-6N times of terminals. A discharge display lamp and a discharge tube are connected parallelly between every two of the common terminal 0 and the 1N-6N leading-out terminals, a wiring plug is connected with the device leading-out terminals via an experimental line, and the whole amplifying device is placed in an insulating plastic device shell with a box cover. The acquiring and amplifying device of the passive AC micro-current of the present invention enables the work efficiency to be improved substantially, is low in device manufacture cost, and possesses certain application and popularization values.