The application of optical modules in rail transit systems is reflected in signal transmission and network communication. Compared with traditional copper cable connections, optical modules consume less energy when transmitting data, which is very beneficial for reducing the overall energy consumption and operating costs of rail transit systems. Optical modules can convert electronic signals into optical signals and transmit them through optical fibers to achieve data transmission and signal control within rail transit. Optical transmission technology has the advantages of long-distance transmission and anti-interference. It can transmit various low-speed control signals through optical transmission without packet loss, ensuring the stable operation of rail transit. The transmission of control signals is the basis for maintaining the normal operation of rail transit. It is responsible for transmitting the operating status, control signals, fault information, etc. to the control center, dispatching center, etc., which can improve the safety and stability of rail transit system engineering.