This study, based on the historical archives of the workers' congress of a state-owned enterprise ( Y Factory ) and interviews with workers, analyzes the process, authority, functions, and participant roles of Workers' Congress since 1987, attempting to identify the driving forces for changes in the Workers' Congress system. The study asserts that the external driving forces include the political missions assigned to the Workers' Congress by the Party during different historical periods, the objective need for improving the modern enterprise management system with Chinese characteristics, and the changing role of government governance strategies across periods. The internal driving forces mainly consist of the dual motivation of "legitimacy" and "efficiency" in state-owned enterprises, the continuous enhancement of workers' awareness of rights protection and their ability to participate in governance, and the increasing clarity of trade unions' responsibilities in providing rights protection services. To provide strong support and protection for the reform of state-owned enterprises, hence we should further strengthen the construction of the Workers' Congress system, and fully leverage its governance effectiveness.