The weight checker is mainly composed of conveying part, weighing part and sorting part. The products to be inspected and weighed in queue on the assembly line are conveyed by a conveyor belt to increase the running speed and ensure sufficient spacing between products to avoid having two products on the weighing table at the same time. After the products enter the weighing platform, the system recognizes the products to be inspected into the weighing area according to the external signals (photoelectricity, threshold). The weighing section completes the acquisition of the weight signals and sends them to the controller for processing to obtain the dynamic weight value of each product. The sorting section is used to transport the products that have completed the inspection out of the weighing area and to reject the products that do not pass the weight test. Depending on the shape and weight of the product, the rejection can be done by air blowing, pusher, flap, etc.