An energy saving for an air compressor is provided, including an inlet end of an inlet pipe being provided with an air filter, a connection end of the inlet pipe being connected to an inlet side of a compressor, an outlet side of the compressor being provided with an outlet pipe, an outlet end of the outlet pipe being connected to an air reservoir, an air supply side of the air reservoir being provided with an air supply pipe, mainly in that one or more accelerated pressurization pipes may be concatenated on the inlet pipe or outlet pipe or air supply pipe, the interior of the accelerated pressurization pipe is a through hole, the inner peripheral surface of the through hole is provided with several spiral grooves thereon, as an air flows through said accelerated pressurization pipe, the air flow is guided by the several spiral grooves naturally to rotate.