The utility model provides a low-voltage cabinet electric energy parameter online monitoring apparatus based on carrier wave communication. The apparatus comprises a power module, and a sampling module, a signal processing module, a CPU module and a display storage module which are successively connected. The sampling module communicates with a low-voltage power line of a low-voltage cabinet through a carrier wave module; the carrier wave module is integrated by a power line interface signal driving circuit, and the driving circuit comprises a modem chip; and the CPU module comprises a PIC single-chip microcomputer chip, an analog-to-digital conversion chip and a data registering unit, and the signal processing module comprises an ARM processor and an active low-pass filter. A periphery circuit can be greatly reduced, and a high-efficiency integration function is realized. The apparatus provides functions of measurement, monitoring and protection, can form an intelligent information monitoring protection apparatus through a carrier wave communication interface and the low-voltage power line of the low-voltage cabinet, and has a quite high industrial application value.