The invention discloses a blocking protection mechanism and method for an agricultural product finishing conveying line. The mechanism includes a first motor, a pallet, a transmission device, side blocking plates and inner blocking plates, wherein the first motor is a cylindrical structure, the pallet is horizontally arranged at the bottom of the first motor, and the bottom of the pallet is horizontally provided with the transmission device. The mechanism is advantaged in that conveyor line tracks are blocked through matching of the side blocking plates at two ends of the mechanism and slots among the three inner blocking plates, that agricultural products on the four conveyor line tracks are blocked by the mechanism at the same time is guaranteed, the agricultural products are prevented from falling out when being transported by the tracks, and the conveying stability of the agricultural products is guaranteed; the second motor rolls in a rolling groove of a track through a roller, that the side blocking plates and the inner blocking plates are more smoothly moved through movement adjustment is guaranteed, rubbing damage between the side blocking plates and the inner blocking plates and the tracks is avoided, and the side blocking plates are matched with the inner blocking plates to make the blocking position of the tracks more precise and suitable.