Manually altering the output flow and load by experienced operators is the most widely used way when the power system power flow calculation has no feasible solution.To find out the critical causes while restoring the power flow solvability，this paper proposes a practical power flow restoration optimization model，with the absolute value of bus injection deviation as the optimizing objective and the problem solved by the primal-dual interior point method.The proposed method is able to find out the improper bus injections and optimize the system to obtain solvable power flow calculations.Simulations on Institute of Electrical and Electronics Engineers（IEEE）standard systems and practical bulk power systems have proved the effectiveness and correctness of the proposed method.The calculation scale capability and calculating efficiency is qualified for practical applications.