The present invention provides a temperature rise characteristic automatic detection device of a low-tension current transformer. The temperature rise characteristic automatic detection device comprises a control and data acquisition system, a current generation device, a low-tension current transformer, a switch, an electronic load and a temperature sensor. The control and data acquisition system is in bidirectional connection with the current generation device; the output end of the current generation device is connected in series with the input end of the low-tension current transformer; the output end of the low-tension current transformer is connected in parallel with the electronic load through the switch; and the temperature sensor is fixed on the low-tension current transformer. The detection device provided by the invention may complete characteristic automatic detection of a plurality of current transformers at once without personnel participation in the whole process, and therefore the detection efficiency is greatly improved.