The invention discloses a flow-diagram generating method. The flow-diagram generating method includes the steps that a main process and a sub-module are designed, wherein the main process comprises a main process inlet, a sub-module port and a main process outlet, the sub-module comprises sub-module nodes, and the sub-module nodes comprise sub-module inlet nodes, sub-module outlet nodes and sub-module interrupt nodes; a connection relationship between the sub-module and the sub-module port is established. By means of the flow-diagram generating method and device, cross-platform development can be supported, dependence resources are small, and installation of third-party software is reduced.