Fiber optical rotary joint have many advantages that other slip rings do not have. In different industries, Fiber optical rotary joint are suitable for a variety of different environments. It can be applied in extreme harsh external environment, such as thousands of meters deep sea, ultra-low temperature, high pressure can work normally. Under the condition of high magnetic current interference, it can also work normally, not affected by electromagnetic induction at all, and the safety factor is particularly good. The fiber optical rotary joint can be reused in multiple modes or multiple groups of modules, and several signals or data streams can be transmitted at the same time on a fiber line. The high-speed characteristics of optical lines are used to improve the capacity, speed and scalability of the route. The disadvantage of fiber slip rings is that they are difficult to link when defective or damaged ones appear in the slip ring installation. So operating in a harsh environment, there must be more advanced other maintenance.