Abstract: In order to further understand the influence of Reynolds number on the low-pressure turbine endwall flow, the Transition SST turbulence model was adopted to conduct numerical simulation with four Reynolds number conditions ranging from 0.6×10⁵ to 3.0×10⁵. The results showed that the numerical simulation method could accurately describe the flow in the low-pressure turbine. In the condition of low Reynolds number, the boundary layer separation at the rear part of the suction surface was easy to occur, and the size of the separation bubble was large. With the decrease of Reynolds number, the total pressure loss at the outlet section increased gradually. The increase amplitude of the average loss and the area of the high loss zone both showed a nonlinear growth trend. The separation zone at the rear part of the suction surface was the gathering zone of low-energy fluid, which was the main reason for the rapid increase of total pressure loss in the flow passage. Passage vortex continued to develop after leaving the flow passage, and constituted the main source of continuous increase of loss in downstream region of cascade with vortices in the wake zone.