The invention relates to a low-voltage electric energy measuring, mounting and connection analyzing comprehensive practical training device which comprises a PLC, a virtual power supply and a low-voltage electric energy measuring gauge, wherein a current transformer simulation device for fault training is arranged between the current output end of the virtual power supply and the current input end of the low-voltage electric energy measuring gauge; a junction box with an impedance fault simulation function is arranged between the voltage output end of the virtual power supply and the voltage input end of the low-voltage electric energy measuring gauge; the PLC is used for controlling the current transformer simulation device for fault training and the junction box with the impedance fault simulation function to carry out fault setting. The low-voltage electric energy measuring, mounting and connection analyzing comprehensive practical training device is capable of simulating various faults and carrying out secondary voltage drop measurement setting, current transformer polarity setting and phase sequence setting.