The invention discloses a cold machined compressor casing. The compressor casing is characterized by being formed through connecting a main body, an air inlet pipe and an air outlet pipe, wherein an air inlet is formed in the main body; an air compression wheel cavity is formed below the air inlet; an air outlet is formed in one side of the main body; a connecting shell is arranged at the outer side of the main body; and the air inlet pipe is provided with a pressure relief intake port. The compressor casing has the following technical effects: the main body, the air inlet pipe and the air outlet pipe of the compressor casing are respectively manufactured by a cold working method of aluminum plate punching, so that traditional complex machining methods of production of precoated sand mud cores, melting of aluminum ingots, chemical degassing, metal casting, sand vibration, perforation, cutting, polishing, sand blasting, shot blasting, energy wasting in numerical control machining and harmful emission are saved, and the production of the main body and the pipes of the compressor casing is standard; and the air inlet pipe and the air outlet pipe are manufactured by multiple angles, and are respectively connected with the main bodies of the compressor casings with various model numbers, so that the configuration requirements needed by factories are satisfied, and a lot of manpower and financial resources are saved.