The commonly used tastes of sweet and sour were respectively set to six concentrations system as the test samples for ranking ability screening of sensory assessors. In consideration of the sensory adaption, 12 assessors were asked to rank three times to each taste. Firstly, the accuracy of every assessor was evaluated by Spearman test. And Kendall test was used to evaluate the repeatability of the assessor. Finally, the ranking ability of each assessor was evaluated and analyzed comprehensively through fusion the data characteristics of accuracy and repeatability by clustering analysis. The results were showed that No. 5 assessor need to be eliminated for his poor performance and No. 3 assessor need to be trained more, while No. 1, 6, 7, 8 assessors showed good ranking ability and No. 2, 4, 9, 10, 11, 12 could directly carry out the test because of their excellent ranking ability. It was also found that W value of Kendall test and r_s value of Spearman test were overall positively related. However, W value of Kendall test could distinguish the ability more accurately among assessors. This paper provides theoretical guidance and practical experience for assessor screening and maintenance in sensory analysis laboratory.