The present invention relates to a data transmission method, apparatus, and system, where the method includes: receiving, by a base station, a Multimedia Broadcast Multicast Service MBMS service transmission request and MBMS service data that are sent by a core network device; after receiving the MBMS service transmission request or the MBMS service data, sending, by the base station, an MBMS service paging message in a cell served by the base station; and sending, by the base station, the MBMS service data to user equipment UE according to the MBMS service transmission request. According to the present invention, a dynamic notification message initiated by a network can be received, and when the network needs to send MBMS service data, a UE can receive the MBMS service data in time.