In view of the problems of complex structure, excessive loss and low speed in the fiber optic rotary joint(FORJ), a high-speed single-mode FORJ structure is proposed, and its performance is tested. The loss of optical signal transmission in FORJ is analyzed and studied. The experimental results show that the designed single-channel single-mode FORJ can transmit optical signal at high speed of 8000 r/min, the loss is 19.6 dB, the maximum impact load is 20 m/s2, and the maximum radial amplitude of the rotating input shaft is 0.63 mm, which can adapt to the harsh working environment.