Background: The “Health Code”, a Chinese version of contact-tracing Apps, has played an important role for COVID-19 containment in China. Its effectiveness depends on public acceptance. In order to obtain the benefit that the App can bring, people are supposed to share their personal data. A “benefit-risk” calculus that based on others’ participation then unfolds.

Objective: The present study combines technology acceptance model (TAM) and social exchange theory to understand the psychological mechanism of public acceptance of the “Health Code” from a reciprocal perspective.

Methods: A questionnaire survey was conducted on March 2021 in a sample of 3000 Chinese netizens (mean age 32.5 years; 51.0% male). A moderated mediation model was tested and verified by utilizing PROCESS macro, with covariates well controlled.

Results: Reciprocity had an indirect effect on accepting attitude towards the “Health Code” mediated by perceived risk and perceived usefulness, while part of this effect was negatively moderated by risk perception towards COVID-19.

Conclusions: The acceptance of the “Health Code” was examined to be a reciprocal process that had technological characteristics of data sharing and contextual characteristics of public health crisis. To promote public acceptance of contact-tracing Apps for COVID-19 containment, it is necessary to evoke reciprocity among the public both ideologically and visibly, to manage their “benefit-risk” calculus by presenting the Apps’ usefulness and guaranteeing data protection, and to take corresponding measures according to different crisis situation.