Carbon fiber composites have great application prospects in the field of rail transit. In order to study the application of carbon fiber composite materials in rail car end boxes. Firstly, the carbon fiber paving structure was designed, and then the product performance of carbon fiber car end box was studied by finite element analysis calculation and sample test verification method. The research results show that the weight of the car end box of carbon fiber composite is about 45% of the weight of carbon steel and stainless steel box, about 72% of the weight of aluminum alloy box, and the weight reduction effect is remarkable. The static strength and fatigue life of the box are the test results of insulation withstand voltage and protection grade all meet the standard requirements and have passed the test verification. The carbon fiber composite car end box can be used and promoted on rail transit.