By constructing a differentiated technical-transformation model for substation, the technical upgrading scheme of secondary equipment was evaluated, and the differentiation and precision of secondary-equipment technical transformation were realized. Firstly, through analyzing history information records, relevant regulations and standards of secondary equipment, combined with the actual operation of substation, the evaluation index system of reforming scheme was constructed. Then, the evaluation rules were perfected, and the calculation model and quantification method of each index were given. Thirdly, the triangular intuitionistic fuzzy number was introduced, a new score function was defined to improve the fuzzy analytic hierarchy process(FAHP), and a non-additive multi-attribute decision-making model was established. Finally, in order to verify the validity of the improved model, an actual case of differential technical transformation was adopted, and the evaluation results are obtained with better discrimination.