Abstract: In urban light rail transit systems, the flame retardant performance of optical cables used for communication signals was directly related to fire safety. The paper, in accordance with the B₁ grade flame retardant requirements of Classification for Burning Behavior of Electric and Optical Cables(GB 31247—2014), analyzed the specific application scenarios of different flame retardant grades. Experimental research was conducted from multiple aspects such as structure and materials, and the factors influencing the flame retardant performance of B₁ grade optical cables and the future technological development direction were analyzed.