When the transmission line icing occurs in extreme low temperature weather, in order to make the grid control center ice melting quality and the planning timeliness to meet the requirements of grid scheduling and operation. This paper designed an ice melting auxiliary decision system based on multi-source and multi-dimensional data of transmission line, which was according to grid ice disposal regulations from provincial grid control centers. It connected the energy management system, planning management system, load forecasting system, ice coverage monitoring and forecasting system and other automation systems, and could obtain and integrate the grid operation data, planning data, load forecasting data and ice coverage data in real time, assess the risk of grid ice coverage accidents in the current and future time periods, and generate the DC ice melting plan according to the set rules, and carried out a static calibration and stability calibration of the generated ice melting plan. Simultaneously, to solve the problem of long time-consuming verification for ice melting plan, a preliminary ice melting plan generation method based on dynamic planning was proposed, which could quickly filter out the unreasonable scheme, reduce the computational amount of the scheme verification, and improve the speed of generating the ice settlement scheme.