The invention discloses an automatic voltage stabilizing power source device which comprises a normally-open switch, a third contactor, a time delay, first and second contactors, a voltage reduction rectification device, a storage battery pack and a voltage detector. The normally-open switch is connected with a first electrode of an alternating current power source, one end of a coil of the third contactor is connected with the other end of the normally-open switch, the other end of the third contactor is connected with a second electrode of the alternating current power source, and a first normally-open switch of the third contactor is connected with a starting normally-open switch in parallel. A coil of the time relay is connected between the normally-open switch and the alternating current power source. One ends of coils of the first and second contactors are sequentially connected with an auxiliary switch of the time relay, a third normally-open switch of the third contactor and the alternating current power source in series, and the other ends of the coils of the first and second contactors are connected with the alternating current power source. The voltage reduction rectification device is connected with the alternating current power source through a first normally-open switch of the first contactor. The storage battery pack is connected with the voltage reduction rectification device through a second normally-open switch of the second contactor. The voltage detector is connected with the storage battery pack. The auxiliary switch of the voltage detector is connected with an auxiliary switch of the time relay in parallel. The power supply quantity of the automatic voltage stabilizing power source device is stable.