The embodiment of the utility model discloses air compressor trouble on -line measuring device, including PLC, acquisition station, network server and user terminal, wherein, PLC is connected with the air compressor electricity, the acquisition station is connected with PLC, network server and user terminal electricity respectively. Compared with the prior art, an embodiment of the utility model discloses an air compressor trouble on -line measuring device, can utilize the acquisition station to pass through PLC and realize real -time on -line measuring to air compressor's running state, effectively improve failure analysis's reliability and reduce the failure analysis processing time greatly.