1) lifting equipment are usually structures are large, complicated, to complete the lifting motion, a horizontal movement. For example, a bridge crane to complete lifting, traveling with the car running 3 campaigns Portal crane to complete hoisting, luffing, rotating and traveling 4 campaign. During the work, often moving in different directions simultaneously, technology is difficult. 2) crane the lifting of heavy weights varied, load is changing. Some heavy objects weighing hundreds of tons and thousands of tons, some objects for dozens of meters, shapes are irregular, granular, thaw status, inflammable and explosive dangerous goods, lifting complex and dangerous process. 3) most lifting equipment, need in larger of space range within run, some to installed track and wheels (as crane, and bridge hanging,); some to loaded Shang tire or track in ground Shang walking (as car hanging, and track hanging,); some need in wire rope Shang walking (as passenger, and freight overhead ropeway), activities space larger 4) some lifting mechanical need directly carrying personnel in Guide, and platform or wire rope Shang do lifting movement (as elevator, and lifting platform,), its reliability directly effect personal security. 5) more exposed, the active parts of lifting appliances, and direct contact with the crane operators (such as wire rope and hook), the potential number of accidental risk factors. 6) operation environment is complex. From a large iron and steel complex, to modernize ports, construction sites, railway, a popular tourist destination, has a crane in operation; workplaces often have special high-temperature, high-pressure, inflammable, explosive, transmission lines, risk factors such as strong magnetic, pose a threat to equipment and operating personnel. 7) in the lifting industry often require more coordination, and common. An operation requirements, including directing, bundling, transmission operations staff with skilled, coordinated action, take care of each other. Workers should have the capacity to deal with emergency. Close cooperation among multiple operators, there is often greater difficulty.