The invention relates to a reinforced fiber composite sleeper for supporting railway tracks. The reinforced fiber composite sleeper is one made from reinforced fiber materials, fiber felts or weaving cloth through resin impregnation, formed by the pultrusion of a forming die for designing the shape of the section and solidified in the forming die. The invention overcomes the defects of the known techniques, has ideal strength and elasticity and good insulating property compared with the common concrete sleeper and the anticorrosive wooden sleeper, and ensures the safe running of the trains. In addition, with the good elasticity, the reinforced fiber composite sleeper greatly enhances the whole elasticity of the track structure and reduces the influence on roadbeds from the vibration of the trains and the environmental pollution from the noise of the trains during running; with the good insulating property, the reinforced fiber composite sleeper has no influence on the track circuits so as to ensure the safe running of the trains. The invention has the advantages of simple manufacturing, easy forming and short production period, and is capable of realizing the mechanical and continuous production. Besides, the length of the reinforced fiber composite sleeper can be cut and processed according to the determined length requirements, and the waste sleepers can be treated and recycled easily.