[Objective] The advantages, disadvantages and applicability of various analysis methods of multi-year observation data of sediment transport modulus in small watersheds were studied, in order to provide references for selecting scientific methods to describe the characteristics of multi-year sediment transport modulus observation data. [Methods] Based on the observation data of sediment transport modulus in four small watersheds, through the comparative analysis of four methods and their combinations, including statistical eigenvalue, de-extremum arithmetic mean, frequency of erosion intensity grade, and box-whisker plot, the description methods with wide applicability and objectivity were explored. [Results] The statistical arithmetic mean and median could hardly represent the concentration and general level of multi-year sediment transport modulus. Although the de-extremum arithmetic mean had the tendency of reflecting the general level of data, it sacrificed the extreme value and its information for decision-making. The frequency of erosion intensity grade reflected the distribution of data in intensity classification. Box-whisker plot could show the concentration, dispersion and the number of abnormal data. [Conclusion] Various methods have their own advantages and disadvantages in characterizing the multi-year observation data. In order to describe their concentration and dispersion comprehensively and objectively, various methods can be used to make full use of their advantages and avoid their disadvantages. Box-whisker plot has good objectivity and applicability in displaying the multi-year data of small watershed.