<p>The prevailing understanding of the regeneration process in supercritical carbon dioxide (S-CO₂) cycles is rooted in multi-stage compression regeneration. However, this approach does not represent the ultimate stage in the development of S-CO₂ cycle regeneration. Its inherent discontinuities impose an upper limit on efficiency improvement and hinder ideal matching with broad-temperature-range heat sources. To overcome this limitation, this study proposes a continuous regeneration method. We have developed an end-stage partial compression cycle that enables continuous adjustment of the regeneration intensity. Theoretical analysis reveals that the net work of the superposed cycle is the key driver of efficiency variation. Further mathematical derivation establishes a criterion for predicting efficiency changes and identifies the pivotal roles of variations in the split flow ratio and enthalpy difference. The model is rigorously validated against two representative scenarios: one where the derivative of the net work behaves as a continuous function, and another where it exhibits discontinuity. The results demonstrate that this method transcends the conventional discrete paradigm of multi-stage compression, allowing for the systematic exploration and approach towards the theoretical efficiency limit of S-CO₂ cycles within the regeneration framework, while providing a fundamental solution for achieving precise matching between the cycle and heat sources.</p>