The present invention discloses an internal combustion engine, comprising a compressor, a combustion chamber, a pipeline, a spray pipe, an oil feeder, a driving device, a first safety device, a second safety device, an electric ignition device, a rack, a first bracket arranged on a top of the rack, a second bracket arranged on an upper part of the rack, a third bracket arranged on a lower part of the rack and a fourth bracket arranged on a left part of the rack. The compressor comprises an inner shell and an outer shell, wherein the inner shell comprises an upper pressing plate and a cylindrical plate; the cylindrical plate can move up and down in the cylindrical plate slot; and an outlet is formed in a non-protruding part at the bottom of the outer shell. The internal combustion engine has simple structure and high efficiency.