针对水石流颗粒粗、粘性小的特点，提出了利用水槽进行分段模拟水石流的设想。首次通过几何变率解决难度较大的阻力相似问题，改变了以往过度加糙的方式；通过变粒径比尺的方法消除了模型沙级配不连续相似的问题，较好地实现了固体物质级配相似，达到了泥石流的密度相似和输沙相似。通过水槽概化模型试验实例，对本方法进行了验证。 In view of the characteristics of coarse water and small viscosity of water stone flow, the idea of ​​using water tank to simulate water stone flow in stages was proposed. For the first time, geometric resistance is used to solve similar problem of difficult resistance and change the way of over-roughness in the past. The problem of discontinuity of model sand distribution is eliminated by variable-size-ratio method, Gradation is similar, reaching a similar density of debris flow and similar sediment transport. The method is validated through the example of a generalized tank model test.