<p>Existing research mainly focuses on the perspective of digital platform developers and examines the advantages of platforms. However, there is still insufficient analysis of why participating enterprises enhance their supply chain resilience (SCR) after engaging in platform boundary-spanning search (PBS) activities through digital platforms. This study aims to investigate, from a resource orchestration perspective, how platform boundary-spanning search, heterogeneous resource acquisition (HRA), and alliance portfolio diversity (APD) are interrelated and jointly influence supply chain resilience. This study employs SPSS 26.0, SmartPLS 4.0, and AMOS 28 to test the proposed model using a covariance-based structural equation modeling (CB-SEM) approach. Through stratified sampling, data were collected from 234 senior supply-chain managers. Common method bias was preliminarily assessed via multicollinearity tests, and content validity was established using item-level and scale-level indices. Structural relationships and mediating effects were analyzed with AMOS 28 and SPSS 26.0. The results indicate that platform boundary-spanning search via digital platforms enhances enterprises’ supply chain resilience. Both heterogeneous resource acquisition and alliance portfolio diversity serve as mediating variables in this relationship. Furthermore, a chained mediation effect exists between these two factors. By emphasizing the role of resource orchestration, this study fills the research gap between platform boundary-spanning search and supply chain resilience. It identifies the crucial roles of heterogeneous resource acquisition and alliance portfolio diversity in improving the effectiveness of supply chain resilience. Moreover, the findings provide theoretical guidance for enterprises seeking to enhance their resilience through boundary-spanning search activities on digital platforms.</p>