The invention discloses a portable fault diagnosis tester applied to a petrochemical production device, comprising an instrument shell, a hardware mainboard, a CPU (Central Processing Unit), a memory, a hard disk, a power supply, a rechargeable battery, a minisize liquid crystal display, a display card, a minisize keyboard, various communication interfaces, a plugin multi-path AD/DA data collector and the like. The fault diagnosis tester can uninterruptedly collect on-site data all day long through simple system arrangement, and the sampling frequency can be set. The invention has small volume, light weight and convenient carrying, solves the bottleneck problem that the fault diagnosis technology is applied to a practical industrial field, has the advantage that the fault diagnosis testercan be used after a network cable is plugged especially for a petrochemical production device provided with a DCS system or a PLC (Programmable Logic Controller) or an intelligent instrument, therebythe invention is very convenient to use.