The invention relates to the technical field of aircraft fault detection and discloses a real-time monitoring system for aircraft fault detection. The system can monitor the current infrared thermogram, audio signal and vibration frequency of an electrical device and compare the current infrared thermogram, audio signal and vibration frequency with the normal infrared thermogram, audio curve and vibration frequency, when the electrical device is abnormal, the infrared thermogram, the audio signal and the vibration frequency are obviously changed, abnormity can be obviously found through comparison, then an alarm is given in time to remind a worker, the infrared thermogram, the audio signal and the vibration frequency are used for monitoring the electrical device at the same time, the monitoring is more accurate, the fault position of the electrical device can be accurately positioned, the heavy work of complete maintenance is avoided, the fault position can be directly maintained, thedesign is novel, and the system has the advantages that an electrical device on an airplane can be monitored in real time, and the fault position on the electrical device can be accurately positioned.