This paper combines the power outage loss caused by load shedding with the optimization problem of load shedding during power shortage, and proposes a load shedding model that seeks the minimum power outage loss under the system’s security and economic constraints. The model is a kind of optimal power flow. In order to reduce the complexity of solving the model, this paper adopts an improved linear programming algorithm to solve the model. With the help of Jacobian matrix, the objective function and constraints of the system are linearized and the linear optimal solution in the iterative space of control variables can be found. Through multiple iterations the scheme with the minimum power outage loss is obtained that satisfies various constraints while the total power generation cost of the system is minimized The correctness and superiority of the model and algorithm are verified in the IEEE14-bus system.