Abstract: In the new era, volunteer service plays a unique role in China's social governance system. As a significant component of volunteer service, university student volunteer service contributes substantially to modernizing the social governance system and enhancing governance capabilities. Based on in-depth research at Beijing universities and literature review, this paper summarizes four characteristic advantages of capital university students' volunteer service participation in grassroots social governance, namely policy, field, intellectual, and brand advantages. Through empirical comparison, it systematically analyzes four typical models and their effectiveness, alongside existing practical challenges in ideological education, supply-demand matching, incentive mechanisms, and support systems. Finally, a "Four in One" working mechanism is proposed for the normalized participation of capital university students' volunteer services in grassroots social governance, aiming to provide reference for enhancing the contribution efficacy of university student volunteer services to social governance.