The invention provides a method for measuring user loop impedance through an intelligent ammeter. The method comprises steps of for any user n, measuring user power supply voltage at the i time so as to obtain a voltage value Vni, and measuring user load current so as to obtain a current value Ini; measuring user power supply voltage at the j time so as to obtain a voltage value Vnj, and measuring user load current so as to obtain a current value Inj; and calculating loop impedance according to the following expression: loop impedance=(Vni/Vnj)/(Inj-Ini). According to the invention, through the existing intelligent ammeter, the voltage and the current are measured, so measurement of the loop impedance is achieved.