Abstract: To find out the cause of the accident which the goods fell because of the wire ropes of a general purpose bridge crane fracture at a factory, the fractured wire ropes was tested physically and analyzed chemically, and the structure of pulley block of the wire rope and the device off the tank was analyzed. The results indicate that the wire ropes fracture was one-time big stress fracture because extrusion wear made the wire rope can’t bear large load. The proximate cause for the accident was that the design of the device off tank for the wire ropes had serious defect and led the wire rope easily released from the pulley block and ran on the bushes, which would produce serious sliding friction and make the wire rope wear and deformation.