This article addresses the issue of the lack of effective weighing methods in the tread feeding section of tire building machines, which leads to missing weight data and affects tire quality traceability. A sinking weighing device integrated into the conveyor roller bed is designed. This device detects the arrival of the tread through a photoelectric sensor, and the weighing tray and L-shaped support rod are driven up and down by a guiding cylinder. The net weight of the tread is accurately measured using a differential weighing method. This structure is compact and highly compatible, suitable for both new model design and retrofitting of old equipment, providing an effective solution for improving tire product quality control.