Qualitative analysis-quantitative description in written language-qualitative analysis and quantitative analysis in mathematical language should be unified and complementary; Qualitative analysis is the basic premise of quantitative analysis, and quantitative analysis without qualitative analysis is blind and worthless; Quantitative analysis makes it more scientific and accurate, and qualitative analysis can draw extensive and in-depth conclusions. Quantitative analysis is a method to establish a mathematical model based on statistical data, and use the mathematical model to calculate the indexes and their values of the analyzed object. Qualitative analysis is a method that mainly relies on the intuition and experience of the analyst, the past and present continuity of the analysis object and the latest information to judge the nature, characteristics and development and change law of the analysis object. Comparatively speaking, the former method is more scientific, but it requires advanced mathematical knowledge. Although the latter method is rough, it is more suitable for ordinary investors and economic workers when the data is insufficient or the mathematical foundation of analysts is weak. However, it must be pointed out that although the two analytical methods have high or low requirements for mathematical knowledge, qualitative analysis and quantitative analysis cannot be completely separated. In fact, modern qualitative analysis methods also need to use mathematical tools to calculate, and quantitative analysis must be based on qualitative prediction. The two complement each other. Qualitative analysis is the basis of quantitative analysis, and quantitative analysis is the embodiment of qualitative analysis. Only flexible combination can achieve the best effect. Different analysis methods have their own characteristics and performances, but they all have one thing in common, that is, they generally analyze and explain problems through comparison. It reflects the quantity, quality, benefit, consumption and development speed through the comparison of various indicators or the same indicator in different periods, thus providing conclusive information for identification and judgment.