The invention relates to a network source converting and voltage-stabilizing device which is used for converting a domestic network source into other international different standards of power supplies and stabilizing the voltage when a load changes. An electric motor is powered by the network source; the electric motor is connected with a three-phase alternating current (AC) generator through a coupling so as to realize the conversion of the network source; and the size of an excitation current in an excitation coil of the generator is controlled by the device when the load changes, so that the change of the output voltage of the generator caused by the load is compensated. The network source converting and voltage-stabilizing device comprises a transformer, a voltage amplitude detection circuit, a voltage frequency detection circuit, a load current detection circuit, a manual control circuit, a main controller, an IGBT (Insulated Gate Bipolar Transistor) driving circuit, an IGBT driving module, an adder circuit, a display system and a remote monitoring system. According to the network source converting and voltage-stabilizing device, the conversion efficiency is high, the voltage of an output power supply is stable, and the network source converting and voltage-stabilizing device can be remotely monitored, so that the network source converting and voltage-stabilizing device has the advantages of high safety, strong practicability, and easiness for the promotion and application in port ultra-high-power grid power conversion plants.