The invention discloses a method for extending participant types, which comprises the following steps that: a service system realizes certain participant extension class through an abstract class provided by inheritance workflow, and realizes an abstract method provided by the abstract class, wherein the abstract method is used for returning a participant list and the participant types; the participant extension class is registered in a specific configuration file of the workflow; and after an instruction that a user selects participants, the flow definition is loaded into the workflow. Through the method, when conventional participant types cannot meet service demand, development personnel do not need to manually perform secondary development on the workflow, which improves the efficiency of service processing.