The elevated temperature tests on four relatively large-scale reinforced reactive powder concrete （RPC） beams and a reinforced normal concrete （NC） beam were performed under constant bending load， followed by bending test after exposure to high temperature， in order to evaluate the fire resistance of reinforced RPC beams. The cross-sectional temperature filed and deflection development at the mid-span position were measured under elevated temperature. The influence of the control temperature and the wrapped mortar layer on the flexural performance were also analyzed through the bending test on the specimens after high temperature. The results show that the explosive spall phenomenon of reinforced RPC beams can be effectively avoided by adding 2% steel fiber and 0.3% Polypropylene fiber （volume dosage） into RPC mixture. Control temperature has important effect on the deflection development of RPC beam under high temperature and its residual flexural performance after the elevated temperature test. After RPC beams were subjected to high temperature of 600℃ and 800℃， their residual flexural carrying capacities was decreased by 13% and 24%， respectively. Wrapping mortar layer on the surface of RPC beam can effectively reduce the high temperature damage and improve the residual bending properties after high temperature. Compared with the reinforced NC beam， the reinforced RPC beam exhibits relatively higher mechanical stability and safety after a high temperature test. Based on the equivalent temperature of cross section， calculation formulas are proposed for predicting the flexural mechanical performance of RPC beam after exposure to high temperatures.