Using a door-to-door approach to integrate inter-and intra-city travel times, this paper simulates the changes in regional territorial and population accessibility, spatial equity, as well as the winner and loser cities resulting from High-speed rail (HSR) network development in the Yangtze River Delta, China. HSR network development has a minimal effect on decreasing the disparity in overall territorial accessibility but leads to an obvious decrease in the disparity in population accessibility. Seven types of winner and loser cities are summarised according to their net winner population and stations locations. Poor access to the city centre from HSR stations is a common problem for many cities in the YRD, and more integrated development is needed for future HSR planning and construction.