The invention belongs to the technical field of air compressors, in particular to an air compressor. The air compressor comprises support columns, a base, first rotary shafts, a compressing block, a compressing mechanism, an air cylinder, a motor, a central gear, first gears and the like, wherein the compressing mechanism is arranged on the base through the support columns; the motor which is arranged on the compressing mechanism drives the first gears on the eight first rotary shafts to rotate through the central gear; in the compressing mechanism, the first gears drive the first rotary shafts to rotate, and the compressing block is then driven to move to achieve the aim of compressing air; and then compressed air is stored in the air cylinder, so that stable use is facilitated. The air compressor is novel in structure; the mode of assembling the motor in an annular compressor ring is used, so that on the premise that a certain air compressing amount is achieved, the size of the equipment is greatly reduced; the aim of convenient use, storage and transport is achieved; and a better use effect is provided.