从工程实际需要出发，研究了贯流式水轮机水平扩散型尾水管的水力性能，提出了这种尾水管的设计方法，从理论上分析了其水力损失。然后对这种管和常用的圆方型尾水管进行了模型水力性能对比试验，用五孔测流探针测量了模型尾水管的流速分布．对试验结果进行了分析和探讨，论证了水平扩散型尾水管用于实际工程的可能性。 Based on the practical needs of the project, the hydraulic performance of horizontal diffused draft tube of tubular turbine is studied, and the design method of draft tube is proposed. The hydraulic loss is theoretically analyzed. Then, a comparison of the model hydraulic performance between the pipe and the commonly used round-shaped draft tube was carried out. The flow distribution of the draft tube was measured with a five-hole flow probe. The test results are analyzed and discussed, demonstrating the possibility of horizontal diffusion draft tube used in practical engineering.