Security constrained economic dispatch is an effective technical means to improve the power grid reliability rate, achieve energy-saving and emission reduction, and improve lean management of dispatching plan. Existing security constrained economic dispatch studies focuse on common goals and constraints modeling and optimization algorithm, with less consideration of actual production factors, so the planned result is of low implementation rate and security constrained economic dispatch has practical difficulties in the actual production. In response to these issues, for planning optimization goals, impartial and open power dispatching, shape of the planning output curve and basic data interval processing, this paper presents an extended model of security constrained economic dispatch based on utility. Proposed modeling method is applied to multiple production instances, which proves that the proposed model has engineering practicality in strengthening impartial and open power dispatching accuracy and improving plan output curve shape and the implementation rate of the planned results.