The invention belongs to the technical field of air compressors, and relates to a low-noise structural oilless air compressor which comprises a cylinder, a cylinder cover and a piston, wherein the piston is provided with a sealing ring or a sealing leather cup made of a self-lubricating material, a crankcase is tightly connected with a crankcase cover plate and forms a crankcase intake muffler, an air intake one-way valve is arranged at an air intake or an air intake passage of the crankcase intake muffler communicated with the outside atmosphere, a damping pad is arranged between an exhaust valve plate and a valve seat, the valve seat is connected with a silencing cap, a crank pin is made into the shape of a spline or similar to the spline, a heat insulation hole or a heat insulation slot is arranged on a connecting rod body, and a heat insulation pad is arranged at the joint of a fastening bolt and the piston or a connecting rod. The low-noise structural oilless air compressor has the advantages that the air intake noise is low, the working temperature and the mechanical noise of a bearing are low, and an auxiliary balance block is arranged on a cooling fan, thereby reducing the vibration amplitude of the compressors, and effectively reducing the body vibration noise.