The present invention relates to a cloud-based API metadata management method and management system. The cloud-based API metadata management method comprises the steps of: installing, by an API tool installation unit of a cloud server, an API tool by loading the API tool stored in a database; defining, by the API tool installation unit of the cloud server, a standard API and generating, by an API generation unit, an API for each hospital server; and testing, by a test unit of the cloud server, the generated API for each hospital server, and modifying data when there is error data, and storing and distributing data and the API for each hospital server when there is no error data.