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