Abstract: In view of the poor underground environment of coal mines, the difficulties in fiber welding, and the safety accidents caused by sparks generated by hot fused fiber at high temperature, a renewable fiber cold connection device was developed. Through the device, the underground optical fiber is cold-connected to eliminate sparks from the root source and reduce the underground coal mine safety accidents; through the OV slot of the device, the cold connection device is filled with the matching liquid for many times to ensure the reproducibility of the device. Starting from the structure, method, how to reduce the loss and how to realize the regeneration of the fiber cold connection in underground coal mine, this paper expounds the regeneration of the fiber cold connection in detail. Through field tests, it was found that the device has the functions of reducing the fusion time of optical fibers in coal mines, reducing safety accidents in coal mines.