A service flow transmission method, comprising: receiving (S103, S403), by a terminal, a transmission method of a service flow from a core network network element, wherein a packet data unit, PDU, session to which the service flow belongs supports a plurality of access technologies, the plurality of access technologies comprise a first access technology type and a second access technology type, the first access technology type is a 3rd generation partnership project, 3GPP, access technology and the second access technology type is a non-3GPP access technology, or the first access technology type is the non-3GPP access technology and the second access technology type is the 3GPP access technology, wherein the service flow comprises a first service flow transmitted by using a first transmission method and a second service flow transmitted by using a second transmission method; obtaining (S203, S412), by the terminal, a plurality of addresses from the core network network element, wherein the plurality of addresses comprise a first address, a second address, and a third address, the first address corresponds to the first access technology type, the second address corresponds to the second access technology type, and the third address corresponds to the first access technology type and the second access technology type; transmitting (S104, S204, S413), by the terminal, the first service flow according to the first transmission method of the service flow by using the first address and the second address; and transmitting (S104, S204, S413), by the terminal, the second service flow according to the second transmission method by using the third address; wherein the first transmission method comprises one of a multipath transmission control protocol, MPTCP, method, an MPTCP proxy method, a quick user datagram protocol, UDP, internet connection, QUIC, method, a QUIC proxy method, a multipath-QUIC, MP-QUIC, method, or an MP-QUIC proxy method, the second transmission method comprises one of a transmission control protocol, TCP, method, a TCP proxy method, a UDP method, and a UDP proxy method. receiving (S103, S403), by a terminal, a transmission method of a service flow from a core network network element, wherein a packet data unit, PDU, session to which the service flow belongs supports a plurality of access technologies, the plurality of access technologies comprise a first access technology type and a second access technology type, the first access technology type is a 3rd generation partnership project, 3GPP, access technology and the second access technology type is a non-3GPP access technology, or the first access technology type is the non-3GPP access technology and the second access technology type is the 3GPP access technology, wherein the service flow comprises a first service flow transmitted by using a first transmission method and a second service flow transmitted by using a second transmission method; obtaining (S203, S412), by the terminal, a plurality of addresses from the core network network element, wherein the plurality of addresses comprise a first address, a second address, and a third address, the first address corresponds to the first access technology type, the second address corresponds to the second access technology type, and the third address corresponds to the first access technology type and the second access technology type; transmitting (S104, S204, S413), by the terminal, the first service flow according to the first transmission method of the service flow by using the first address and the second address; and transmitting (S104, S204, S413), by the terminal, the second service flow according to the second transmission method by using the third address; wherein the first transmission method comprises one of a multipath transmission control protocol, MPTCP, method, an MPTCP proxy method, a quick user datagram protocol, UDP, internet connection, QUIC, method, a QUIC proxy method, a multipath-QUIC, MP-QUIC, method, or an MP-QUIC proxy method, the second transmission method comprises one of a transmission control protocol, TCP, method, a TCP proxy method, a UDP method, and a UDP proxy method.