Smart electric meter capable of measuring residual current

A smart electric meter capable of measuring residual current comprises a housing (1), a wiring terminal base (2), a phase line (5), a null line (6), a relay (3), a phase line current sampling resistor (4), a residual current transformer (7) and a circuit device (8). The relay (3), the phase line current sampling resistor (4) and the residual current transformer (7) are disposed in the housing (1). The phase line (5) and the null line (6) pass through the residual current transformer (7). The circuit device (8) comprises a voltage sampling module (81), a signal processing module (82), an A/D conversion module (83), an electric energy metering module (83), a single-chip microcomputer processing module (85), a relay control module (86), a communication module (87), an LCD display module (88), a button module (89) and a power supply module (80). The smart electric meter can perform real-time measurement and recording of the residual current in a user line and has residual-current over-limit alarm event and event recording functions. The smart electric meter only needs to be improved on the basis of an existing smart electric meter, is not high in the improvement cost, does not affect the functions and the outline dimensions of the existing electric energy meter, and is convenient to popularize in large scale.