Plant-soil feedback (PSF) is one of the mechanisms driving species turnover during ecological succession. The species-specific soil pathogen disadvantages the negative feedback species, whereas the positive feedback species maintain their populations through associations with mycorrhizal fungi. However, most studies seldom address the within-species variance in how plants respond to their soil microbes. In this study, we constructed a theoretical model to understand how within-species variance in intraspecific PSF influences the time points of stability and the final stable state in the long-term succession process. Results suggest that the within-species variance in PSF will not lead to different succession speeds or stable states, and the succession outcome largely depends on the average PSF strength in this system. Our findings contrast with the previous understanding, highlighting the critical role of the long-term average PSF in shaping the succession outcome. Further studies that integrate the interspecific PSF into models are required for a better understanding of the succession dynamic.