Abstract: In order to improve the utilization rate of seat resources, this paper studied the optimization model of differential pricing strategy of China's railway passenger transport under linear demand. To maximize the revenue, based on the optimization theory and the total price discrimination strategy, the paper determined the optimal subdivision number of passenger groups and the optimal ticket price of each passenger group. It was concluded that in the off-season of passenger transport, the optimal subdivision number of railway passengers was 3-5, and the optimal ticket price of each passenger group was determined by the subdivision number of railway passenger market segments. The model was applied to the differential pricing of an intercity high-speed railway. The experimental results show that the model can adjust passenger flow and increase revenue.