Primary militia are a crucial component of China's armed forces, and the stability and combat effectiveness of their contingent directly affect the effectiveness of national defense mobilization. However, under the conditions of a market economy and prolonged peace, the characteristics of annual reorganization and high personnel mobility pose challenges to the sustained participation willingness of primary militia. Based on social exchange theory, psychological contract theory, and self-determination theory in organizational behavior, this paper proposes specific measures to enhance the sustained participation willingness of primary militia from four dimensions: optimizing institutional guarantees, innovating management models, strengthening spiritual incentives, and constructing a supportive environment. The research aims to provide reference for strengthening the construction of militia contingents in the new era.