The invention relates to the technical field of workflows, in particular to a Java-based cross-platform workflow implementation method and system. The Java-based cross-platform workflow implementationmethod is characterized by comprising the following steps: S1, function registration: obtaining classes, interfaces, methods and parameters from a Jar packet, and selectively registering the functionmethods into a function database to facilitate function display, search and function modeling; s2, building a functional process; s3, function process management and service release: performing unified management on the function process templates, providing import, export, edit and delete functions of the function process templates, and realizing process management and release; s4, functional process service operation testing; and S5, function process service calling: calling through a function library web interface. According to the invention, the service process can be flexibly defined, andthe cross-platform establishment of the workflow is supported.