往复式压缩机（reciprocating compressor）或活塞压缩机（piston compressor）是一种由曲柄轴带动活塞驱动的压缩机 。

当曲柄轴往复运动时，会先打开进气阀，关闭排气阀，进气由进气阀进入压缩缸，然后进气阀关闭，活塞运动使压缩缸容积减小，压缩气体，之后排气阀打开，排出高压的气体。像炼油厂、管线输送、天然气处理、化工厂及冷冻机械都会用到往复式压缩机。吹制聚对苯二甲酸乙二酯（PET）的保特瓶时也会往复式压缩机。

相较于其他的压缩机，往复式压缩机的压力及马力数涵盖范围大，为其优点，其缺点是噪音及振动都较其他压缩机要大，而且比较占空间。

A reciprocating compressor or piston compressor is a positive-displacement compressor that uses pistons driven by a crankshaft to deliver gases at high pressure.

The intake gas enters the suction manifold, then flows into the compression cylinder where it gets compressed by a piston driven in a reciprocating motion via a crankshaft, and is then discharged. Applications include oil refineries, gas pipelines, chemical plants, natural gas processing plants and refrigeration plants. One specialty application is the blowing of plastic bottles made of polyethylene terephthalate (PET).