Although co-production between the government and society can improve service outcomes, the two parties may lack the willingness and the capacity to cooperate. Can nonprofit organizations play an active role in facilitating government–citizen co-production? If so, how? The role of nonprofits in social services co-production has received increasing attention, but studies on developing countries are limited. Therefore, this study conducts an in-depth case study of a rural social work institute in Z village, Beijing, China. Using on-site observations, semi-structured interviews, and secondhand materials, it was found that social workers adopted four strategies to engage community officials and rural residents in service co-production. They established trustworthy relationships, facilitated effective communication, fostered shared motivation, and built co-productive capacity. The results showed that nonprofit organizations use third-party roles and professional skills to shape government-citizen interactions through service co-production. These findings can improve rural service provision in developing countries.