Service migration flow control method, server and system

The invention provides a flow control method for service migration, a server and a system, which can be used in the financial field or other fields; the method comprises the following steps: a first server migrates a source code corresponding to at least one service to a second server, a flow controller identifies all current scenes according to a call chain and segments all the current scenes to obtain afirst current scene calling group and a second current scene calling group; the first server executes the first current scene calling group, the second server executes the second current scene calling group, the one or more services are used for realizing a set scene, and a calling field is stored in a data packet of each service; therefore, calling fields of all services for realizing a scene are serially connected to form a calling chain, different calling chains correspond to different scenes, a calling party system does not need to be transformed, the scene is identified through the calling chains, a spec