本文的主要研究内容是国民收入的增长模型。基于分段函数的运用,本文引用了一种分段函数界点判定的方法并将其进行了实际运用。首先本文运用一般的传统指数模型和DUD法确定参数进行了模型拟合。在与上述传统模型对比分析的基础上，可知分段函数法在我国特殊阶段的国民收入增长模型的拟合上有很大的优势，其拟合结果的相对误差要更小。最终，本文通过模型结果对我国的国民收入经济结构进行了初步的分析并提出了几点建议。

The main research content is a model of growth of national income. Based on the use of sub-functions, this paper presents a segmented functioncritical point to determine the method and its practical application. Firstly, this paper uses traditional exponential model and DUD method to determine the parameters of the model fitting. Based on the analysis in comparison with the traditional model, we can see the sub-function method has a great advantage in the national income growth of China's special stage model fitting, fitting the relative error smaller. Ultimately, the model results on the economic structure of China's national income preliminary analysis and some suggestions.