With the continuous expansion of the power system, ensuring the stable operation of transmission lines is of paramount importance. In order to accurately assess the status of each section of transmission lines in the same region, this paper proposes a method that integrates grey relational analysis with Gaussian cloud model. The paper elaborates on the construction method of the feature quantity system, as well as the principles, algorithms, and technical details of grey relational analysis and Gaussian cloud model. Application examples have demonstrated the accuracy and effectiveness of this evaluation method in transmission lines. The research results enable qualitative and quantitative assessments, effectively identifying weak segments in the lines and providing strong support for dynamic capacity expansion and power inspection. The research methodology of this paper has practical application value, contributing to enhancing the safety and economy of power systems and making significant contributions to promoting the sustainable development of the energy industry.