有压泄水洞的泄流能力是一个涉及其规模、尺寸的关键问题，是设计中必须解决的水力学问题。从有压恒定流的伯诺里方程出发，对有压泄水洞的流量计算进行了理论分析，并以已建工程试验数据为基础，提出了流量系数的经验计算式。

The discharge capacity of a pressure spillway tunnel is a key problem involving its scale and sizes, and it also is a hydraulic issuewhich needs to be solved in design. From Bernoullis energy equation of steadyuniform pressure flow, the discharge computation way of pressure release tunnelis analyzed theoretically. In combination with experimental data of several practical projects, the experience formula of coefficient of discharge is suggested.