As a popular application, social question-and-answer (Q&A) platforms have similar functions and it is relatively easy for users to switch from a platform to another one. This may lead to users’ defection. From a push–pull-mooring perspective, this work examined the determinants of user switching between social Q&A platforms. We found that both push factors (dissatisfaction and fatigue) and pull factors (content quality and user experience) positively affect switching intention, which leads to switching behavior. The mooring factor (switching cost) has a negative moderation effect on switching intention. These results suggest that social Q&A platforms can improve content quality and users’ experience, and reduce their dissatisfaction and fatigue, thus preventing users’ switching and retaining them.