Abstract: When the multi-hole sluice is opened partially, 3D hydraulic jump and secondary hydraulic jump will occur. In order to avoid or reduce the damages to the anti-scour facilities placed behind the sluice and the river channel, this paper aims at the situations where one and three consecutive holes of the plain gate are open respectively, and four training walls with different lengths are placed at the stilling pool. Studies of relevant characteristics of hydraulic jump, flow pattern and flow velocity are carried out by the hydraulic model tests and 3D numerical simulation. The scale of the hydraulic model is 1:100, and the numerical simulation adopts the RNG k-ε turbulence model and the VOF method. The research results show that the three consecutive holes are open with the opening of 1m under the conditions of model tests, with the training wall lengths of 0.5, 0.6, 0.75 and 1 times of the length of the stilling pool, compared with the case without training wall; the sequent depth has decreased by 4.16%, 1.66%, 1.94% and 2.22% respectively; and the distance of the secondary hydraulic jump has reduced by 17.14%, 14.29%, 2.86% and 1.43% respectively. The sequent depth and the distance of the secondary hydraulic jump have reduced to the largest degree when a training wall whose length is 0.5 times of the stilling pool is placed in the stilling pool, and the flow velocity is most uniform over the apron in this case. The test results can provide a technical support for the management of engineering operations including energy dissipation by the baffle blocks or the stilling basins located behind the sluice.