The invention belongs to the field of the power line carrier communication, and discloses a multi-mode communication device in a power line communication system. The multi-mode communication device comprises a core processing unit, a coupling unit, a sending unit and a receiving unit; the output end of the core processing unit is connected with the input end of the coupling unit through the sending unit, the input end of the core processing unit is connected with the output end of the coupling unit through the receiving unit; the sending unit comprises a multi-carrier sending end communicationunit, a first single-carrier sending end communication unit, a second single-carrier sending end communication unit and a first analog front-end unit; the receiving unit comprises a multi-carrier receiving end communication unit, a first single-carrier receiving end communication unit, a second single-carrier receiving end communication unit and a second analog front-end unit. Various communication rate application scenes can be taken into consideration when the power line communication performance is guaranteed, the multi-mode communication device can be extensively applied to the power linecarrier communication field and the single-carrier and multi-carrier hybrid network communication field.