Taking the Wulong Yinpan Pumped Storage Power Station as the study object,this research investigates the influencing factors and differences on navigation safety under different working conditions of the pumped storage power station.Using a 1:50 scale hydraulic model,combined with acoustic Doppler velocimetry (ADV) and particle image velocimetry (PIV) methods,the flow characteristics at the inlet/outlet and downstream river sections are quantified.The results show that under low-flow conditions with the inlet/outlet operating at full capacity,the flow velocity in the main navigation channel increases significantly by 30%-100%,though the overall velocity remains below 0.25 m/s.During high-flow flood conditions,the topographic changes induced by the inlet/outlet structure are the primary cause of adverse navigational flow patterns.The slope formed by platform excavation at the intake/outlet creates pronounced lateral deflection flow,generating a maximum transverse velocity of 0.30 m/s,with its influence extending up to 21 m into the river channel.Additionally,a large-scale backflow zone of 29-43 m(backflow velocities exceeding 0.20 m/s)is formed downstream of the slope.Based on the research results,it is recommended that subsequent engineering optimizations focus on smoothing the platform topography to ensure gradual flow smoothly transition.The research results can provide technical references for navigation safety assessments of pumped storage power stations in similar mountainous river channels.