Based on the CFX solver, aiming to improve the negative flow patterns in the sumps of a small sluicelateral pumping station with navigation function, numerical orthogonal simulation tests of the airfoil deflectors were carried out. The results show that if there are no rectifying measures, the flow pattern in the sumps is disordered with large recirculation zones from the No.1 to the No.3 sump. The velocity distribution is not uniformandthe axial velocity distribution uniformity is only 76.84%. By arranging four airfoil deflectors with elevation angles of 25° at 1D away from the entrance of the sump, the recirculation zones basically disappear. The velocity distribution is modified and the axial velocity distribution uniformity is 90.2%, increased by 13.36%, with a more uniform and symmetric flow pattern. The airfoil deflectors can eliminate the recirculation in the sump so that the stream is forced to flow along its pressure and suction surface, and the uniformity of the velocity distribution is improved.