Abstract: Both thirty-three concrete stub columns reinforced by prestressed steel hoops (PSHC) and nine unreinforced columns were tested under axial compression. The studied parameters were the hoop ratio (the spacing of hoops and the concrete diameter), the prestressing level and the initial axial compression ratio. The influences of these parameters on the carrying capacity and deformation capacity of PSHC were obtained and discussed. The results show that the bearing capacity and deformation capacity of the PSHC can be improved by 107% and 540%, respectively, compared with the comparison column. The reinforcement effect will become better with the increase of the hoop ratio. When the prestress ratio increases gradually, the carrying capacity of PSHC increases gradually and the peak strain decreases gradually. The initial axial compression ratio has no obvious influence on the reinforcement effect, the PSHC can be used as a non-unloading reinforcement method. Based on the experiment results, a prediction equation was proposed and verified by the comparison of prediction values and test data in this investigation and other references.