Piston reciprocating compressor

The utility model relates to a piston reciprocating compressor which has a main body, wherein a crank shaft is arranged in the main body, cranks are arranged on the crank shaft and pistons are connected to crossheads which are connected with the cranks and are arranged in a cylinder. A compression system is composed of the cranks, the pistons and the cylinder and is arranged according to a combined form of opposite movement and contraposition. The utility model reasonably arranges an alternate angle between the cranks, and the inertial force furthest reaches the balance. Consequently, the reliability and the practicality of the use are raised.