The invention provides a linear oil-free compressor which comprises a first cylinder, a second cylinder arranged just opposite to the first cylinder, a first piston and a second piston; the first piston sleeves in the first cylinder and is lubricated with air in the first cylinder; the second piston sleeves in the second cylinder and is lubricated with air in the second cylinder; and the first piston and the second piston moves in a same direction, when the first piston sucks air, the second piston presses the air, and when the first piston presses air, the second piston sucks the air. The compressor provided by the embodiment of the invention adopts air for lubrication, so that the structure of the compressor is simplified, and the size of the compressor is shortened; and meanwhile, the first piston and the second piston alternately works, so that smooth running of the compressor is realized, and mechanical vibration and working noises of the compressor are lowered.