In order to improve the real-time performance of power grid control decision-making,a scheme is proposed in the paper. This scheme decomposes the economic optimization problem that takes into account the expected fail-safe constraints into the main problem of the ground state optimal power flow with the goal of minimizing the power generation cost and the sub-problem of the expected fail-safe check. At the same time,a decomposition and coordination algorithm based on tunable space slice parallel is proposed to solve the problem without alternate iterations. First of all,the adjustable space is sliced to form multiple slicing schemes according to different proportions. Based on the parallel computing platform and the slicing schemes,the primal dual interior point method is used to solve the base-case optimal power flow master problem. Secondly,security check of contingencies is carried out by parallel computing for different optimized cases. Then,the solution with the minimum cost is chosen from the safe solutions. Finally,the effectiveness of the proposed method is verified by cases in the regional comprehensive energy system of a city in Guizhou province.