An auxiliary propulsion apparatus of an air vehicle may include an engine mounted in a fuselage of the air vehicle, a generator configured to be driven using power from the engine, a compressor configured to be driven by the engine or the generator, a battery configured to store electricity generated by the generator, an electricity distributor connected to the generator, the battery and the main propulsion apparatus and configured to distribute electricity generated by the generator to the battery and to a main propulsion apparatus, and at least one nozzle device configured to jet high-pressure gas, supplied from the compressor, to an outside of the fuselage.