Reliability analysis is the premise for reinforcement and maintenance of an existing highway tunnel. In order to understand the structure reliability of an existing highway tunnel, a fuzzy mat-ter-element evaluation method was put forward based on entropy weight according to the fuzzy matter-element analysis method. Firstly, levels of inspection results were regarded as objects of matter-element and composite fuzzy matter-elements were constructed considering such factors and their evaluation indexes as cracks of concrete lining, lining thickness, concrete strength, cavities behind the lining and water leakage conditions. Secondly, reliability evaluation results of the existing tunnel structure were obtained by calculating the relevancy. Lastly, fuzzy matter-element evaluation model was effectively used to evaluate reliability of one highway tunnel structure.