Abstract: Flow at the outlet of a drop shaft structure is difficult to achieve uniformity under the influence of its bend and straight sections. Meanwhile, reverse flow tends to occur near the diversion orifices. A RNG k-ε turbulence model was adopted in this study with experimental verification to make a three-dimensional numerical simulation on flow characteristics near the bend outlet of a drop shaft, and the effects of bend type and straight pipe length on the flow uniformity have been analyzed. The results show that if the length of straight pipe section is fixed at 2D (D is the diameter of straight pipe), a bend of gradual contraction can produce more uniform outflow than a regular bend of equal diameter (fixed and equal to the diameter of contraction outlet). If equal diameters are adopted, the outflow uniformity of two bends is comparable when the length of straight pipe adds 6D ~ 8D. The results are significant in guidance for design of the drop shaft inlet and outlet of pumped storage plants.