<p>Social ties have been considered as the core factor driving individuals’ informal social control. Previous studies confirmed the informal social control effects of delivery riders. However, it is not clear what social ties influence such effects. This study conducted a questionnaire survey on 699 delivery riders in 71 communities of Guangzhou. It aims to explain the willingness of participating in informal social control of delivery riders by their social ties, including ties to family and friends, work-related ties, and ties to police. Results of multilevel linear regression models suggest that their ties to police has the strongest influence, followed by work-related ties, and then ties to family and friends. Specifically, ties to police, including cooperation willingness with police and satisfaction with police, correlate positively with participation willingness, whereas visibility of police shows a negative association. Work-related ties positively influence participation willingness, with higher familiarity with work community and positive relationships with customers/security in their work community increasing willingness. In term of ties to family and friends, ties to family weaken willingness, while ties to friends enhance willingness. This study expands research scope by introducing delivery riders and systematically differentiating their social ties, offering insights for policies to engage riders in urban governance.</p>