Abstract: To study the shear performance of high-strength reinforced reactive powder concrete simply supported beams without stirrups, based on the test results of four RPC beams' shear failure experiment under concentrated load, the influence of steel fiber volume ratio on diagonal crack development pattern, load-deflection curves, shear toughness of beams and diagonal crack width is analyzed. Results show that steel fiber can reduce the diagonal crack spacing, increase the shear-compression zone height, and improve the shear ductility of the beam. Steel fiber has less effect on shear toughness of beams at the initial stage of loading, but it has great effect on shear toughness of beams after the initial yield point. The greater the steel fiber volume ratio is, the smaller the diagonal crack width and the greater the peak load are. Its influence on peak load is more obvious than the effect on mid-span deflection.