There are complex flow patterns in the entrance area of the upstream approach channel of ship locks in the curved reach，such as reflux and oblique flow. The hydraulic characteristics of navigable flow in the upstream approach channel and the entrance area of ship locks are studied by changing the scheduling method of a check gate with the combination of physical model tests and numerical simulations. The results show that with the upstream inflow of 1 000 m3/s，the maximum lateral flow velocity and reflux velocity upon opening the fourth hole in the middle by the check gate are greatly smaller than those upon opening the eighth hole on the left；with the upstream inflow of 1 500 m3/s，the maximum lateral flow velocity and reflux velocity upon opening the fourth hole in the middle are greater than those upon opening the eighth hole on the left. When the flow rate is consistent，the flow velocity distribution of the measuring points on the section varies greatly. Controlling the scheduling method of a check gate can effectively weaken the reflux and oblique flow effect and ensure navigation safety.