This paper proposes a new approach for finding the minimum number of post-contingency corrections to relieve overload. The security-constrained optimal power flow (SCOPF) problem with AC power flow constraints can be formulated as mixed integer nonlinear programming (MINLP), which is an NP-hard problem. A two-stage approach—screening and detailed analysis—is utilized to solve the non-convex MINLP and can achieve computational tractability. We provide numerical results with the proposed approach on two test systems: the 39-bus and the 1354-bus systems.