Abstract: With the development of new power system with new energy as the main body, its volatility, randomness and intermittence determine the higher requirements for the reliability of power supply, and more intelligent equipment and technologies are needed to assist the operation and maintenance, so as to improve the stability of the system. However, at present, there is a lack of an auxiliary decision-making platform to support the operation and maintenance of transmission lines and disaster emergency response under the background of new power system, and massive data and various algorithms can't be integrated and applied, so the traditional application platform can't effectively support the power supply level of transmission lines。Under the background of new power system, based on the characteristics of new power system, this paper mainly introduces how to build a power transmission intelligent decision-making platform from three aspects: "improving the ability of environmental prediction and control, improving the ability of equipment risk identification and assessment, and improving the ability of operation and maintenance, disaster prevention and mitigation", so as to achieve strong support for new power system。