The invention relates to a grabbing and detecting mechanism for parts. The grabbing and detecting mechanism comprises a bottom plate, a grabbing mechanism, a detecting mechanism, a carrying mechanism, a part bin and an unqualified product bin. The part bin and the unqualified product bin are fixed to the bottom plate. The parts are arrayed in order in the part bin; a square groove hole is formed in the bottom plate, the detecting mechanism is installed on the bottom plate and located on the square groove hole, and the detecting mechanism is used for detecting the appearance and sizes of the grabbed parts; the carrying mechanism is installed on the bottom plate, the grabbing mechanism is installed on the carrying mechanism, the grabbing mechanism is used for grabbing the parts arrayed in order in the part bin, and the carrying mechanism is used for achieving shifting of part grabbing and detecting action; the unqualified product bin is used for storing unqualified products, and the unqualified products detected through the detecting mechanism are put in the unqualified product bin under the driving of the carrying mechanism. Through the arrangement of all the mechanisms, the parts can be automatically grabbed and detected, the detected unqualified products are conveyed to the unqualified product bin, and the grabbing and detecting mechanism is simple in structure and suitable for various machining environments.