Abstract: The entropy TOPSIS model was used to compare the effects of Sevage method, acetonitrile method and trichloroacetic acid (TCA) method for removaling crude Bletilla striata polysaccharide (BSP) protein, and to explore the rationality of entropy TOPSIS for BSP deproteinization system evaluation. Based on the comprehensive score of BSP retention rate and protein removal rate, the optimal treatment conditions were screened out. Nine evaluation indicators including monosaccharide components, oxidative radical scavenging ability (ORAC), and half scavenging concentration of DPPH radicals (IC₅₀) were constructed. Supplemented by UV and FTIR, the entropy TOPSIS was used to evaluate the results of three BSP deproteinization programs. After comprehensive score, the best extraction times of sevage method was 1 time. At same time, the protein removal rate was 22.9%, and the polysaccharide retention rate was 99.11%. The optimal mass concentration of the TCA method was 10%, when the protein removal rate was 70.64%, and the polysaccharide retention rate was 70.03%. Compared with the ORAC values and IC₅₀ of the three polysaccharide, it was found that the value of polysaccharide ORAC treated by the acetonitrile method was higher than that of the positive control group (P<0.05), and the polysaccharides treated by the Sevage method had the strongest antioxidant activity. The BSP deproteinization evaluation system was analyzed by the entropy TOPSIS model, and the sevage method deproteinization effect was the best and the expected result. The results showed that the entropy TOPSIS model could be used in the evaluation of BSP deproteinization system.