In order to investigate the influence of the bottom dip angle of contraction section of the dustpan-shaped inlet on the hydraulic performance of the passage, the physical model and hydrodynamic model of the inlet structure of the dustpan-shaped inlet were established. The Reynolds N-S equation and RNG κ-ε turbulence model were adopted to simulate the flow field of the passage with 5 different underside inclinations in the inlet contraction section. The results show that the bottom dip angle increases has a great influence on the velocity distribution of the inlet contraction section and the throat of the winnowed dustpan-shaped inlet passage, and the scheme of the bottom dip angle increases the density of the srteamline distribution and the curvature of the throat, with the increase of flow velocity, the hydraulic loss of the passage is large, and the velocity distribution uniformity of the outlet section of the passage is low; The scheme with small bottom dip angle makes the streamline distribution smooth and the throat streamline curvature becomes slow, the velocity decreases, the hydraulic loss of the passage reduces, and the velocity distribution uniformity of the outlet section of the passage increases; The magnitude of the inclination of the bottom surface of the intake contraction section has no obvious influence on the weighted average angle of the flow velocity of the outlet section of the passage. Hydraulic performance of passage with different bottom dip angles was analyzed. When the bottom dip angle of the inlet contraction section of the dustpan-shaped inlet passage is less than 3°, the water flow in the inlet passage is smooth, the hydraulic loss is small, and the flow pattern at the outlet of the passage meets the water inlet conditions of the pump impeller chamber.