The new and old alternate train diagrams, serving as a pivotal transitional operational scheme bridging current and forthcoming schedules, are of paramount importance in ensuring a seamless transition of the railway transportation system from its current state to an updated one. This paper extensively examines the characteristics of transitional train diagrams, selecting indicators from multiple dimensions such as transport efficiency, orderliness, stability, and passenger service quality to construct a comprehensive evaluation framework for these transitional schedules. Subsequently, the entropy method is employed to precisely reflect the discriminative capability of each indicator, followed by the assignment of appropriate weights. Furthermore, through the integration of the Technique for Order of Preference by Similarity to Ideal Solution approach, the resemblance between these indicators and the ideal solution is assessed, thereby computing the comprehensive scores of each diagram plan and evaluating the quality of the transitional train diagrams based on these scores. Finally, the feasibility of the evaluation methodology is validated through small-scale numerical illustrations.