A convergent charging method includes determining, by a session management function (SMF), a charging type of a first data flow and a charging type of a second data flow, where the charging type is online charging or offline charging. The method further includes sending, by the SMF, a first message to a charging server using an online-offline convergent charging session based on the charging types of the first data flow and the second data flow, where the first message includes a first online charging request of the first data flow or a first offline charging request of the second data flow, and the online-offline convergent charging session is used to send the first online charging request and the first offline charging request.