Photomultiplier tube (PMT) is one of the important probe a space optical detection applications. Due to the limitation of manufacturing process, the photomultiplier tubes have great individual difference. This paper designed a set of applied in space-borne laser atmospheric detection radar automatic test system of photomultiplier tube life evaluation, and established a scientific testing methods and processes. Based on key parameters such as photomultiplier tube and dark current and photoelectric response test, monitoring and analysis, the life characteristic of photomultiplier tube was studied and evaluated .