泥沙模型试验需要控制模型进口流量及其含沙量，根据泥沙模型的供沙方式，将其分为水沙分离型和水沙混合型加沙系统。在水沙混合型模型试验中，模型的含沙量不能随模型流量快速变化，存在较大的控制滞后。在分别详细介绍水沙分离型和水沙混合型加沙系统的控制过程和工艺特点后，提出按照新型水沙分离型加沙工艺的加沙方法，在模型进口补充加沙，使水沙混合型加沙系统具有水沙分离型加沙系统的特点。这样可以解决水沙混合型模型的控制滞后的问题，同时提高了模型含沙量的控制精度和自动化程度。

The intake discharge and sediment concentration of a model need to be controlled in sedimentation model experiment. According to the sandsupplying mode, the sandfeeding system can be divided into watersand separate type and watersand mixed type. In the experiment of the watersand mixed sandfeeding system, there is a large control delay problem, because the sediment concentration can’t change with discharge rapidly. This paper introduces the control procedure and technological features about the two types of sandfeeding system. It puts forward an improved sandfeeding method by which sands are complemented at inlet. The new method has characteristics of the watersand separate sandfeeding system, and also solves the delay which exists in the watersand mixed sandfeeding system, thus improving the accuracy of the sediment concentration control and automation of the model.