The invention relates to an AC permanent magnet gain transformation device and a voltage regulating and control method thereof. The device adopts the structure that a permanent magnet or a permanent magnet component is additionally arranged in a traditional transformer structure, the magnetic pole face of the permanent magnet is clung to a lamination iron core so as to ensure that inherent permanent magnetic potential of the permanent magnet can be led out under the excitation of excitation current of a primary winding, and is stacked and compounded with the excitation magnetic potential in a closed-loop lamination iron core master magnetic circuit, and as a result, at the output end of the secondary winding, the induced electromotive force stacked by the excitation magnetic flux and the permanent magnet magnetic flux can be inducted. The voltage regulating and control method comprises the following steps: inputting the impulse current of certain amplitude value into the primary winding to ensure that a compounded excitation effect can be generated; changing the pulse count of the impulse current in unit time so as to change and regulate the input and output power of the AC permanent magnet gain transformation device. According to the invention, the power transmission efficiency of the transformation device is further improved, and inherent depletion of the traditional coil winding and the lamination iron core is compensated, and the energy is saved.