The application provides a service data splitting method and apparatus. A SeNB receives distributed service data from an MeNB based on a first expected volume of distributed data, and buffers the distributed service data. The SeNB determines a data volume change status of the distributed service data when a preset period expires, where the data volume change status includes a buffered-data volume reduced state, a buffered-data volume accumulated state, and a received-data volume insufficient state. The SeNB adjusts the first expected volume of distributed data based on the data volume change status to obtain a second expected volume of distributed data. and the SeNB sends the second expected volume of distributed data to the MeNB, so that the MeNB performs splitting based on the second expected volume of distributed data.