To analyze the diversity of potato germplasm resources and screen elite germplasm， 197 potato germplasm resources were used as research objects. Seventeen phenotypic traits were identified and evaluated by comprehensively applying Simpson index， Shannon-Wiener index， coefficient of variation， correlation analysis， principal component analysis， cluster analysis， piecewise linear regression， and multiple linear regression analysis. The results showed that the Simpson index of 12 qualitative traits ranged from 0.441 to 0.714， and the Shannon-Wiener index ranged from 0.752 to 1.410. Tuber flesh color exhibited the highest diversity with abundant variations. Among the 5 quantitative traits， the coefficient of variation of tuber reducing sugar content reached 31.61%， while plant height was relatively small （14.21%）. The Simpson index of 5 quantitative traits ranged from 0.845 to 0.859， and the Shannon-Wiener index was ranged from 2.008 to 2.077. Traits such as starch content and stem diameter had higher Shannon-Wiener index， indicating greater potential for genetic improvement. Stem diameter showed strong stability over two years， while tuber reducing sugar content was an environment-sensitive trait. Correlation analysis revealed that plant height was positively correlated with stem diameter， yield， and starch content， but the correlations were not significant. Plant height was significantly negatively correlated with tuber reducing sugar content， and tuber yield was extremely significantly negatively correlated with tuber starch content. For quantitative traits， principal component analysis extracted 3 principal component factors with a cumulative contribution rate of 66.408%. By combining the membership function with principal component analysis to calculate comprehensive scores， 10 elite germplasm resources were screened out， including Kexin No.27， Huashu No.13， and Chuanyu No.117. Cluster analysis based on the comprehensive score （C value） of the 197 tested germplasm divided them into 4 clusters， with significant differences among clusters. Through piecewise linear regression and multiple linear regression analysis， complex nonlinear relationships were converted into combinations of multiple simple linear intervals. Plant height， stem diameter， and tuber yield could be used as key indicators for evaluating the comprehensive value of potatoes. The results of this study provide a scientific basis for the utilization of potato germplasm and variety breeding.