The invention discloses a transformer substation monitoring system based on edge computing. The system comprises an external monitoring device, an internal monitoring device, an acquisition device, aprocessing device, a judgment device, a storage device, a first alarm device and a supervision platform, and is characterized in that the external monitoring device is arranged outside a transformer substation monitoring point; the internal monitoring device is arranged in a transformer substation monitoring point; the acquisition device, the processing device, the judgment device, the storage device and the first alarm device are connected with one another and correspondingly arranged near a substation monitoring point; the processing device is used for preprocessing, matching and identifyingthe image data acquired by the external monitoring device; and the storage device is in wireless connection with the supervision platform, and the supervision platform comprises a database, a secondalarm device and a display terminal. High-quality image resources are obtained, detection and recognition of various different parts and defects are achieved, various factors of the transformer substation are comprehensively monitored, an alarm is given in time and backed up to a supervision platform, and the computing pressure of a cloud processing center is relieved.