This study aims to evaluate the Fuzzy Technique for Order Preference by Similarity to Ideal Solution (Fuzzy TOPSIS) to assess the interior design diagrams. It can solve the unfair situation of different opinions and evaluations among teachers. Six criteria to assess the interior design diagram were first obtained from the available references. One criterion was deleted using the Fuzzy Delphi Method through the results of experts' questionnaires. The rankings of the assessment in the interior design diagram on students could be justly determined by the Fuzzy TOPSIS. The present study indicates using the proposed Fuzzy TOPSIS to assess the interior design diagram can obtain more reasonable results than those of traditional assessment.