Abstract: Dynamic reactive power optimization（DRPO）is of important significance to improve the operational security and economy of power systems.However,DRPO is a multi-period coupled non-convex mixed-integer-nonlinear-programming problem.In order to solve this problem with high efficiency and high accuracy,a DRPO method is proposed based on the mixed integer second-order cone programming（MISOCP）.In this method,by approximating the non-convex power flow equations to convex second-order cone constraints and equivalently replacing the absolute value constraints with normal inequality constraints,the original non-convex mixed integer nonlinear programming problem is transformed into the convex MISOCP problem while reflecting the AC power flow physics with high accuracy,thus significantly reducing the solving difficulty.By solving the MISOCP problem,accurate solutions are obtained.Case studies based on the IEEE 30-bus system and the IEEE118-bus system indicate the effectiveness and robustness of the proposed method.