The calculation method for section stiffness and mid-span deflection of pre-stressed capon fi- ber reinforcement concrete beam in the different stage was proposed; Calculation formula for average cracks distance and crack width were derived from the traditional reinfomxd concrete theories.Ihe calculated re- salts were compared with the test data, the results show that the value fr}n this simplified calculation for- mula is in good agreement with the experiment data.