G3-PLC technology is the new generation technical specification, which has many advantages such as low rate, high reliability and strong anti-interference ability etc. But due to the operating frequency limit, communication failure phenomenon often occurs when being applied to complex medium voltage distribution networks, which cannot guarantee a high reliable communication. Hence a new generation device of power line carrier communication is designed independently with G3 technology. The bandwidth of the device can be flexibly adjusted between 7. 8 kHz to 10MHz, processing units of physical and front-end are implemented in FPGA chip and MAC/convergence processing units work in ARM chip. Both attenuation of signals power and signal distortion rate accord with the relevant standards, test results verify that the research and developed device has a good stability and accuracy when it works.