The utility model relates to a cut -parts stack positioning mechanism, including grabbing device, shoot device, workstation and with grabbing device, shoot device electric connection's controller, the workstation is equipped with two at least detection zones, shoots unit bit in the top of detection zone. The cut -parts that stack needs are shot the device and are acquireed the image information of every cut -parts in placing different detection zones respectively, shoot the device and send the image information who acquires to the controller, and the controller carries out image analysis according to the image information who receives to every cut -parts, and controller drive grabbing device snatchs one of them cut -parts and places at specified region, and controller drive grabbing device snatchs remaining cut -parts, stack remaining cut -parts in proper order and are placing according to the requirement of setting for that stacks in specified region's the cut -parts, realize the accurate positioning that cut -parts stacked, reach the clothing require with pleasing to the eye effect, guarantee product quality, need not manual operation, improve production efficiency.