The invention discloses a PDC (polycrystalline diamond compact) bit tool capable of doing eccentric swing rotation, and belongs to the field of rock breaking tools for drilling equipment. The PDC bit tool comprises an eccentric shaft, a housing body, a PDC bit and a cycloidal shaft, wherein the PDC bit is fixedly connected to the cycloidal shaft; the cycloidal shaft is arranged in the housing body in a matched way and can perform relative variable trajectory eccentric rotation; an eccentric shaft section arranged on the eccentric shaft is arranged in the inner cavity of the cycloidal shaft in a matched way to form a rotary pair; the inner flow channels of the eccentric shaft, the cycloidal shaft and the PDC bit are communicated. According to the PDC bit tool, the alternative cutting trajectory motion is made, so that the stratum penetration capability of the PDC bit can be remarkably improved, the rock breaking efficiency is improved, and the wear rate of cutting teeth is reduced; the PDC bit tool has remarkable technical advantages on difficultly drilled deep strata and high-hardness and high-abrasiveness strata.