针对Ｚ～Ｑ关系数据拟合中出现的具体问题，在文献［１］研究基础上，重点论述了具有两种约束条件的组合应用；提高了原浮动多项式的适用范围，导出了两种模型中约束条件：ｕ（ｘ）、φ（ｘ）及待定系数求解格式，拓展了浮动多项式模型内涵，经资料验证成果合理，为山溪性河流水位流量关系定线电算化奠定了基础。 According to the specific problems appearing in the fitting of Z ~ Q relation data, on the basis of the literature [1], the combinatorial application with two kinds of constraints is emphatically discussed; the applicable scope of the original floating polynomial is improved; and in the two models Constraints: u (x), φ (x) and undetermined coefficient solving format, expand the connotation of the floating polynomial model, verified by the data results are reasonable, and laid the foundation for the computerization of the relationship between the water level and the flow of the mountain stream.