Globally, sustainable procurement is seen as a crucial component of public sector sustainability initiatives. This research investigates the internal and external barriers to the implementation of sustainable procurement in China’s public sector. Primary data for this research were gathered using survey techniques from 287 respondents who were procurement officials at higher education institutions that are part of the public sector. Twelve hypotheses were developed based on the conceptual model and literature review and evaluated using SEM-AMOS in order to look at the correlations between the variables. The study’s findings demonstrate that employee competency, employee motivation, training programs, financial aspects, management commitment, government rules and regulations, unavailability of green products, supplier capacity, and third-party pressure statistically influence the sustainability of public procurement. At the same time, green practices, the ineffectiveness of green products, and prices of green items had statistically no significant influence on sustainability in public procurement. This is a crucial effort to identify the factors that influence sustainable purchasing in China’s public colleges. This study draws interest from stakeholders and adds to the scant body of knowledge on sustainability in developing nations. In addition, this research is crucial for creating a roadmap for China’s long-term sustainable development in the area of procurement.