The invention discloses an anti-theft device for low-voltage residential users and an anti-theft method. The device includes a meter body, a user mobile end and a power grid management center, whereinthe meter body is in mutual communication with the user mobile end and the power grid management center through the wireless network, the bottom of the meter body is provided with a linkage mechanismlinked with incoming and outgoing wires and a trigger mechanism mechanically connected with the linkage mechanism to trigger an alarm, the meter body is internally provided with a control mechanism,an input end of the control mechanism is connected with the trigger mechanism, and an output end of the control mechanism mutually communicates with the user mobile end and the power grid management center through the wireless network. The device is advantaged in that connection of power grid lines is monitored very well, occurrence of electricity theft is avoided, the lines are fixed well, when acircuit needs to be maintained, the lines can be quickly disassembled.