Social work and public health have always shared a common mission and vision in promoting human health. However, existing research tends to view social work and public health as two separate fields at both practice and policy levels, and these studies have largely neglected the consideration of how to integrate public health and social work. In the context of the COVID-19 epidemic, the link between the two has been strengthened and health social work has been given more importance. The question addressed in this article is through what mechanisms or practices the social work profession can strengthen its professional status and engage in interprofessional collaboration. Based on key informant interviews and case studies (one community and two cabin Hospitals), this study points out that three legitimacy mechanisms are needed: operationalizing policy, extending value, and completing justification. Furthermore, the future and possible limitations in relation to the development of health social work in China are discussed and specific recommendations are provided. Health social work needs to conduct practices and summarize its experiences and methods, to create a more friendly political environment by translating its results into policies that are conducive to the development of health social work through a political agenda. It needs to improve upon its practical abilities and methodologies, as well as professional education relating to professional values and ethics, in addition to identifying the deeper social needs of residents and discovering new, undeveloped areas of service. Moreover, because long-term change is difficult to justify due to China’s policy agendas, the question of whether the professional status of health social work in the post-epidemic context can be improved is something that needs to be further explored in future studies.