A improved automobile energy-saving and emission reduction oxygen adding optimized air-fuel ratio device mainly comprises a high-pressure oxygen storage tank, a high-pressure filter, a high-pressure electromagnetic valve, a high- pressure debooster, an electric-control pressure regulator, a gas, air and oxygen mixer, a gas input tube, an air input tube, a hybrid filter, a gas, air and oxygen matching sensor, an engine, an air-fuel ratio sensor, a tail gas vent-pipe and an automatic regulator. The invention has the advantages that peracetic combustion of a fuel is performed, and carbon monoxide and hydrocarbon fully react with the oxygen, so that the energy efficiency of the fuel oil is improved and the fuel oil is saved; the gas quickly flames, the temperature rising of the engine is fast, the gas expansion is quick, and the output power of the engine is high; the operation condition of the engine is optimized, and the operation quality and service life of the engine are improved. The tail gas is purified, and the pollution in environment is reduced. The construction is simple, the performance is reliable, the cost is low, and the manufacturing technology is simple. The device can be mounted on various traveling electric vehicles, has great economic and social benefits.