In order to research the impact of bottom hole and slope on the hydraulic characteristics of velocity and flow pattern in fishway, a series of numerical simulation on three different working conditions were done by the k-εturbulence model. The results showed that in vertical slot fishway, the maximum velocity usually appears near the vertical slot, and the velocity at the bottom layer is higher than other layers. The bottom hole at the central baffle would slow down the velocity at the vertical slot, but the velocity would be very high at the bottom hole. When the slope of the fishway changes from 5.2% to 2.6%, the average velocity at the vertical slot decreases more than 20%. It was concluded that the gentle slope is beneficial to the migration of the fish in terms of velocity.
