<p>The precise computation of active earth pressure among groups of deep foundation excavations is crucial to ensuring the stability of such pits. Current calculations of active earth pressure in deep foundation pit groups, based on the theory of semi-infinite soil assumption, have yielded significantly overestimated results. A novel method for calculating active earth pressure was proposed by considering the interaction partitioning of curved slip surfaces in adjacent pits. The proposed method hypothesized that the slip surfaces within finite soil zones between adjacent deep excavation groups exhibit geometric characteristics consistent with cycloidal trajectories. Furthermore, the slip surfaces on either side of adjacent pits with asymmetric excavation were delineated as interaction zones above the intersection point and non-interaction zones below it. Within the interaction zone, a force equilibrium model for a non-isosceles trapezoidal infinitesimal element was introduced. Account was taken of the variability in slip surface curvature and excavation depth, and coupled differential equations were developed to derive the calculation formula of active earth pressure. In the non-interaction zone, the active earth pressure formula was derived through force equilibrium analysis of a right-angled trapezoidal infinitesimal element. The validation case comparison with Rankine theory and other calculation methods demonstrated that the results of the method proposed in this study showed closer alignment with the baseline values. This study can provide a new paradigm for the collaborative design and safety evaluation of pit groups.</p>