[Purpose/significance] Drawing on a series of theories from behavioral economics, we aim to construct a theoretical framework for user health information search mechanisms. [Method/process] Firstly, the behavioral eco⁃nomics theories in existing information search research are reviewed, along with their theoretical contributions to the field of information search research. Subsequently, four components of users' health information search mechanisms were identified: alternatives, outcomes, likelihoods and values. Based on these, four research dimensions of health infor⁃mation search were organized: search or not to search health information, formulating health information search strate⁃gies, selecting health information (sources), continue or stop searching health information. Furthermore, a theoretical framework for users' health information search mechanisms was constructed on this foundation. [Result/conclusion]This study comprehensively addresses the uncertainty in health information search and users' bounded rationality,thereby constructing a research framework that encompasses three subprocess mechanisms: the initiation and termina⁃tion mechanisms of users' health information search, the formation mechanisms of users' health information search
strategies, and the judgment and selection mechanisms of users' health information. These three subprocess mecha⁃nisms clarify the following points, respectively: firstly, users' health information search behaviour is inherently based on the weighing of search costs and benefits; secondly, as cognitive load increases, users develop heuristic search strate⁃gies to simplify health information search; and thirdly, users' judgments and selections of health information are ofteninfluenced by heuristics and various cognitive biases.