China''s railway construction investment is huge, railway finance has formed a large amount of debt burden. In order to realize the financial sustainability of China''s railway industry, the reasons affecting the financial sustainability of the national railway group should be fully understood first. The governance theory is taken as the core, and the factors affecting financial sustainability of China National Railway Group Co., Ltd. are analyzed comprehensively considering various factors. Data are collected through questionnaire survey, and the formation path of railway liabilities is clarified by using the interpretative structural equation model. The results show as follows: the financial sustainability of the national railway group is the result of the comprehensive influence of market governance, social governance and government governance, among which the government governance factor is in the dominant position. It is suggested to reduce the railway industry''s outstanding debts, establish a public welfare transport subsidy mechanism for the railway industry, and promote the implementation of flexible ticket pricing system.