We aimed to construct a convenient evaluation system of potato shade tolerance and explore shade-tolerant germplasm, chlorophyll content, photosynthetic capacity, chlorophyll fluorescence and other parameters of photosynthetic systems of plant leaves under shade at tuber bulking stage. We measured tuber yield per plant and starch content after harvest in 35 potato cultivars (lines). Multiple statistical analyses (e.g., principal component analysis, membership function method, cluster analysis, and regression analysis) were used to analyze the shade tolerance coefficients and evaluate the shade tolerance of the potato cultivars (lines). First, 13 individual photosynthetic parameters related to shade tolerance of potato were converted into six comprehensive indexes by principal component analysis, representing 87.51% of the total information. Then, to obtain the comprehensive evaluation value of shade tolerance (D), we calculated the membership function values for each germplasm and weighted the contribution rate of principal component. Thirty-five potato cultivars (lines) were classified into four shade-intolerance types according to the results of D-value clustering analysis; Eshu10 and Lishu6 were the strongest and weakest shade tolerance cultivars, respectively. Finally, a mathematical evaluation model for potato shade tolerance was established by stepwise regression analysis: D=0.060+0.106Gs+0.214qP+ 0.143NPQ. In addition, the decrease in yield and/or starch content of cultivars (lines) with strong shade tolerance identified by the evaluation system was lower than that of germplasm with weak shade tolerance, so the evaluation system can be used to rapidly evaluate and predict the shade tolerance of potato germplasm.