It needs a scientific and complete index system for a comprehensive evaluation on the safety of foods in some region or some country. And the use of advanced evaluation technologies is also an important work of food safety evaluation. The paper eliminated the redundant data in index membership for object classification by defining distinguishable weight and extracted valid values to compute object membership. The improved algorithm of membership degree transformation includes three calculation steps which can be summarized as “effective, comparison and composition”, which is denoted as M (1,2,3). The paper applied the new algorithm in fuzzy evaluation on the safety of foods. Evaluation results show the validity of the improved model and the model can achieve the dynamic evaluation of the safety of foods in some region or some country.