Social media become an important space where people receive and share up-to-date health-related information during the rapid global spread of the novel coronavirus (COVID-19). While information sharing in social media has been shown to improve relations, reduce stress, and enhance life satisfaction, little is known about reciprocal sharing. Situated in COVID-19 pandemic, this study conceptualizes information sharing as a communication process during which sharers expect the receivers to reciprocate, while receivers feel obligated to return the favor. Building upon social exchange theory and studies on social media sharing, the study tested a model of moderated mediation in which sharing of COVID-19 information was predicted to enhance life satisfaction by encouraging reciprocal sharing, i.e., information reciprocity. Subjective norms, attitudes, and perceived usefulness of the information was predicted to moderate the mediation. The hypothesized mediation was supported by data from a survey of 511 online participants in China. Furthermore, the indirect effect appeared stronger among the respondents who found the information more useful, reported more positive attitude, or perceived more subjective norms. The findings suggest that expected reciprocation may be an important incentive for social sharing, and received reciprocation may be a central part of the mechanism through which sharing benefits the sharer. Policymakers and communicators may need to take information reciprocity into consideration when designing health information campaign to confront communal threats.