Static voltage stability is an idealized concept that assumes infinitesimally small disturbances, which is not suitable for the secure operation of highly nonlinear power systems within the steady-state voltage stability region (SVSR). To address the problem of abrupt shrinkage of the attractive region caused by the boundary crises within the SVSR under large power disturbances, this paper proposes a voltage stability region partitioning method that considers boundary crises, referred to as voltage stability region considering boundary crises (BCVSR). First, the mechanism of boundary crises and their impact on voltage stability are studied through manifold analysis. Next, the theoretical findings are verified through phase trajectory analysis. Bifurcation analysis is subsequently employed to study the influence of parameter variations on the equilibrium sets and dynamic characteristics of direct-drive wind power integration system. Finally, the system’s single- and double-parameter BCVSRs in the space of power injections are partitioned and compared with the SVSR. The results show that under large power disturbances, the proposed BCVSR method effectively excludes regions within the SVSR that are vulnerable to boundary crises, thereby enhancing voltage stability of the system. This provides valuable guidance for power adjustment in practical power system operations.