Node topology identification device and system based on ammeter

The embodiment of the invention relates to a node topology recognition device and system based on an electric meter. The device comprises a power coupling circuit, a direct-current working power supply VCC which processes alternating-current voltage and then outputs the alternating-current voltage to supply power to a main circuit, and a control circuit working power supply VDD which supplies power to a control circuit. The main circuit comprises a first switching tube, and the first switching tube is switched on or switched off under the control of the PWM control signal, so that the main circuit outputs a current with a preset amplitude; the control circuit comprises a second switch tube and a third switch tube and outputs a PWM control signal for controlling the first switch tube; and the constant current circuit comprises a parallel resistor, so that the current output by the main circuit is constant current. The technical scheme provided by the embodiment of the invention can be applied to an intelligent