Characteristics of the equipment according to bolster the side frame of the factory job, drawing on current route advantage for bolster side frame maintenance, can be applied to 8G, Pont 65, K2, K4, K6 and the United States and Russia cast steel bolsters full or partial magnetic particle inspection of the side frame. The workpiece can be circumferential and longitudinal magnetization and demagnetization, composite, disposable magnetic Omni-directional display bolster side frame surface or near-surface cracks, device operation is simple and convenient.