Taking catenary as the research object，a comprehensive evaluation model of catenary health status based on variable weight matter-element extension was established. Combined with the matter-element extension theory and the relevant index standard of catenary，the classical domain of the state information of catenary was set up，and the state parameter matter-element matrix was formed. Meanwhile，using the linear combination of entropy weight method and analytic hierarchy process，the initial weight with both subjectivity and objectivity was obtained. Re-correction using the variable weight theory made the weight reveal the active participation of the evaluation object in the general evaluation process. Finally，the closeness degree function was introduced to evaluate the health level of catenary，and was checked by tests. The example proves the correctness and practi- cability of this model in comprehensive evaluation of catenary health status.