The embodiments of the invention provide a current transformer secondary circuit detection device, which belongs to the electric equipment field and comprises a housing. The front face edge of the housing is provided with a screw hole for the secondary circuit detection device to be installed on the switch cabinet door. The front face of the housing is embedded with a display device to display the state of the secondary circuit detection device. The housing is provided therein with a shunt resistor and a Rogowski coil. The Rogowski coil is connected with the input end of a voltage comparator. The output end of the voltage comparator is connected with the display device. According to the invention, in combination with the output voltage of the Rogowski coil to determine whether to open the circuit or not, it is possible to prevent the damage caused by the circuit opening of a current transformer secondary circuit to the people's life, to reduce the probability of accidents, to increase the working efficiency and to save the working time with load.