The invention relates to a cutting part dust restraining structure. A first dust restraining structure body and a second dust restraining structure body are included. The first dust restraining structure body comprises a boom front end mist spraying device and a roller rear end mist spraying device fixed to the rear end portion of a roller blade, and the design mist spraying direction of nozzles of the roller rear end mist spraying device is located in the tangent line direction of the corresponding circumference on the rear end face of a roller along the corresponding nozzles and is oppositeto the roller rotating direction. The boom front end mist spraying device is fixed to the top of a boom and the position, close to the front end face of the boom, of the left side or the right side ofthe roller, and the design mist spraying coverage area of nozzles of the boom front end mist spraying device is in front of the corresponding nozzles. The second dust restraining structure body comprises a boom rear end mist spraying device, the boom rear end mist spraying device is fixed to the column face, close to the rear end face of the boom, of the boom, nozzles of the boom rear end mist spraying device are arranged in the left-right direction at intervals, and the design mist spraying coverage area is arranged above the front of the corresponding nozzles. The cutting part dust restraining structure is obvious in dust restraining effect, the defect of dust restraining in the roller can be overcome, and meanwhile influences of mist spraying water on the ore charge grade are reduced as much as possible