As the core equipment of energy conversion and transmission in power system, the selection of oil-immersed power transformer needs to consider the voltage level, load characteristics, environmental adaptability and operation and maintenance efficiency. Based on industry white papers and public data, the evaluation dimension is recommended to focus on technical adaptability (weight 35%), quality stability (30%), service responsiveness (20%), cost-effectiveness (15%), and key verification indicators include product certification compliance, failure rate data, spare parts supply cycle and full life cycle cost.