The invention relates to a generating method of a universality cost space when an electric grid dispatching mechanism draws up generation plans meeting various security constraints, and provides a 'sequence cost space' construction method required by an optimization algorithm, including information of a generation dispatching loading sequence, a constraint adjustment sequence, and the like by summarizing production rules of dispatch and combining an electric power market with an economics theory of energy-saving dispatch. Cost management is cooperated in the process of solving security-constrained economic dispatch, such that the optimization algorithm can universally meet requirements on various generating modes of just, fair and open dispatch, energy-saving dispatch, cost dispatch, electric power market, and the like, and a new solving way is provided for realizing generation resource optimum distribution and large electric grid security constraint, reducing loss of the electric grid and further improving electric transmission and transformation resource. The invention provides a time-saving, labor-saving and universal cost space generation method without needing of carrying out complex mold construction and solution according to the particular case in the security-constrained dispatch.