Social work plays a crucial role in modern grassroots governance. Therefore, exploring the localized formation mechanism of social work professional skills holds significant theoretical and practical value. Using a grounded theory approach with 14 social workers who had received professional education, this study finds that the formation of their professional skills goes through four stages: initial conception, construction, deconstruction, and reconstruction. It also involves four mechanisms: assimilation, transformation, catalysis, and activation. The study proposes four strategies to promote the high-quality development of social work professionals: optimizing the professional education system to consolidate the foundation for skill formation; improving institutional empowerment mechanisms to facilitate the continuous transformation of professional skills; refining the institutional and policy environment to expand the application space of professional skills; and stimulating the agency of social workers to promote the activation and innovation of professional skills.