折线型实用堰作为低堰应用于中小型水利工程。通过整理前人研究成果，以及对实测试验资料进行分析，提出了折线型实用堰的界限范围：0.67＜δ/H≤1.5～2.0，且0.5≤P/H，给出了自由泄流时流量系数的计算公式。

The brokenline practical weir as a low weir is being widely used in many middle and small scale water conservancy projects.The paper describes the research results on this weir's discharge capacity.On the basis of summing up the previous research results and through analyzing experimental data,authors proposed a limitation for applying a brokenline practical weir(namely,the ratios of weircrest width to head above weir are more than 0.67 but equal or less than 1.5～2.0, ratios of weir height to head above weir are equal or more than 0.5;the upstream slope of this kind of weir is about 2.0),and gave the formulas for calculating discharge coefficients under free overflow condition. 