According to the normalizationof power grid ice disaster protection, in order to enhance disaster prevention technology and economy of unit, from power grid ice melting technology combines the TOPSIS theory to construct the decision model, and by using the IDSS theory ,the ice melting power system model IDSS which is based on TOPSIS algorithm is proposed. By using the model that is proposed in this article, the calculated results based on TOPSIS to determine the first ice-melting operating area. Finally, through the empirical analysis, verified the validity of the model of decision support system, realized ice-melting decision optimization.