采用二维数值模拟的方法，模拟了表孔溢流坝及其末端的跌坎式底流消力池的二维流场。并分别从调整跌坎高度、在跌坎前增加水平段，以及改变出流角度3个方面对跌坎体型进行修改，通过各方案对比，得出消力池临底流速变化规律。可为工程设计和科学试验工作提供参考。

The flow field of the surface spillway of an overflow dam and the tilling basin with step down floor at the end of the spillway was simulated by 2-D numerical simulation. The shape of the step down floor was modified from three aspects, namely changing the height of the step  down floor, adding a horizontal platform in front of the step down floor and changing the angle of the outlet. By comparing different plans, the rules of velocity variation near the stilling basin were obtained. The study can be regarded as a reference for engineering design and scientific experiments.