Abstract This article addresses the complex legal landscape surrounding Advance Directives (ADs) in the Guangdong-Hong Kong-Macao Greater Bay Area (Greater Bay Area), where distinct legal traditions exist. Presently, discrepancies in AD regulations pose significant challenges, potentially leading to the disregard of individuals’ end-of-life preferences when crossing jurisdictional boundaries. While Hong Kong (with the incoming Advance Decision on Life-sustaining Treatment Ordinance) and the city of Shenzhen stand as pioneers in China with AD legislation, inconsistency persists nationwide. To mitigate these challenges, this article proposes a model law harmonizing AD application in cross-border jurisdictions. Emphasizing the primacy of personal autonomy, the model law advocates for the binding nature of ADs, ensuring legal protection and accountability for physicians who honor individuals’ directives. By bridging legal disparities and safeguarding individuals’ rights, this model law aims to promote consistency and respect for end-of-life preferences in the Greater Bay Area.