A service layout method and device, and a server, used for solving the technical problem of incapability of performing service layout and programming in SDN online. The service layout method of the present application comprises: obtaining a service flowchart of services to be layout, the services to be layout being used for setting a control operation to a transport network, the service flowchartcomprising a plurality of operational model identifiers and a logical connection relation between the plurality of operational model identifiers, the logical connection relation being an execution sequence of the service flowchart; obtaining a scheduling parameter corresponding to each operational model identifier, obtaining a current network state by means of a control layer when the scheduling parameter is a current network resource provided for executing the service flowchart, and verify whether to obtain the current network resource or not according to the obtained current network state; and if the verification is succeeded, generating an executable code for executing the service flowchart according to the scheduling parameter corresponding to each operational model identifier and thelogical connection relation.