石砭峪水库泄洪洞弯段布置为大底坡急流弯道，为调整其水流流态，进行了水工模型试验。根据隧洞已开挖的现状，又要较好的控制洞内水流流态，试验中曾对弯道体型进行了多次修改比较，其中复合圆弧弯道体型较好的控制了急流弯道水流流态。本文结合该工程试验研究，着重对复合圆弧弯道水流特性及其控制急流效果进行了阐述。并提出了急流弯道的初步选型方法。 The curved section of Shiyuyu reservoir spillway tunnel was arranged as the bend of the large bottom slope jet stream. Hydraulic model test was carried out to adjust the water flow pattern. According to the status quo of tunnel excavation, but also to better control the water flow patterns in the cave, the curve has been tested many times the body modification comparison, in which the complex arc curve body shape better control of the jet stream Flow. In this paper, combined with the experimental study of the project, the characteristics of the flow in the composite circular arc and the effect of controlling the jet stream are expounded. And proposed the preliminary selection method of rapid bend.