With the continuous acceleration of the process of urbanization in our country, the influx of foreign population into the city continues to increase, and with it is the inevitable traffic congestion. Therefore, studying the impact of urban rail transit on the price of residential real estate has very important practical significance for future city subway route planning and residents' house purchase plans. First, construct an index system that affects the price of residential real estate. Supported by the extension theory of matter-element entropy weight, an extension model of the influence of urban rail transit on the price of residential real estate is constructed, and the influence level of subway construction on the price change of residential real estate is obtained. The example analysis of residential real estate projects along Shijiazhuang Metro Line 1 confirms the applicability of the extension evaluation model in the research direction of the influence of urban rail transit on the price of residential real estate.