The embodiment of the invention discloses a transformer substation terminal box monitoring system comprising control equipment, data acquisition equipment, communication equipment, a server, heating equipment and automatic fire extinguishing equipment. The data acquisition equipment is used for acquiring a first current temperature and humidity value in a transformer substation terminal box and a second current temperature and humidity value outside the transformer substation terminal box and transmitting the first current temperature and humidity value and the second current temperature and humidity value to the server through the communication equipment. The server is used for processing the first current temperature and humidity value and the second current temperature and humidity value to obtain a processing result and transmitting a control instruction to the communication equipment according to the processing result. The communication equipment transmits the control instruction to the control equipment. The control equipment controls the heating equipment and the automatic fire extinguishing equipment to work according to the control instruction. With application of the transformer substation terminal box monitoring system, condensation generated in the transformer substation terminal box can be eliminated by working of the heating equipment so that the performance of the transformer substation terminal box can be guaranteed and the safety hidden trouble of maintenance personnel can be eliminated.