As an emerging transportation infrastructure, the rapid development of high-speed railways has had a profound impact on social economy and people"s production and life in recent years. Based on urban data and railway data of ten prefecture-level cities in Zhejiang Province, except Zhoushan City, from 2006 to 2019, this paper uses a multi-period double difference method to explore the impact of high-speed rail on the income gap between urban and rural residents. It is found that: (1) The opening of high-speed rail and the increase in the frequency of trains have shortened inter-city travel time and significantly improved urban accessibility. (2) The opening of HSR widens the income gap between urban and rural residents, and affects the income gap between urban and rural residents through the mediating variable of changes in urban accessibility caused by changes in the frequency of trains. (3) There is an advance effect on the impact of HSR on the income of urban and rural residents, from the time when the construction of HSR starts, HSR will facilitate the reduction of the income gap between urban and rural residents in the region.