The invention discloses a cleaning and separating method for wood chips and belongs to the technical field of wood processing. The method comprises a chip screening process and a circulating water washing process; a chip screening and circulating water washing system is adopted; the system comprises a screening machine, a water washing machine and six sequentially communicated sedimentation tanks; the water outlet of the water washing machine is communicated with the water inlet of the first sedimentation tank; the water outlet of the sixth sedimentation tank is communicated with a pump; the water outlet of the pump is communicated with the back washing water inlet of the water washing machine and the wood chip and water inlet of the water washing machine through a flush valve. The cleaning and separating method comprises the following steps: a, a hole is formed in a middle layer screen mesh, near the feed port, of the screening machine, so that the wood chips can scour the screen mesh when falling; b, the enclosing wall of the sixth sedimentation tank is heightened and the water outlet of the sixth sedimentation tank is elevated; c, the opening degree of the flush valve is adjusted; d, the operating frequencies of the flush valve and a blowdown valve are adjusted. Through the adoption of the cleaning and separating method, the problems that as the impurities such as sand in the wood chips are not cleaned completely, device abrasion such as sheet grinding in the follow-up procedures can be solved.