The invention relates to a pulse swing single-unit engine, which comprises a single-unit fuel pot, a gas pot, a catalysis bed, an electric controller, a swing engine, a fuel control electromagnetic valve, and an emergence discharge valve. The invention uses the mixture of high-density hydrogen dioxide and diesel as the single-unit fuel, to be decomposed into high-temperature high-pressure mixture gas via catalysis decomposition to be stored in the gas pot. When the pressure of gas pot reaches preset value, the electric controller can use two aerated switches to start the engine to output swing power directly or output electricity via the generator, while the swing frequency is equal to the switch frequency of aerated valves. The invention has small volume, low weight, high energy density, and wide application, to be used to supply energy in non-oxygen condition or oxygen-lack condition.