A packet sending method, apparatus, and system are disclosed, and related to the communications field. The method includes: A first device receives a first packet including a network identifier of a virtual local area network and an original packet. The first device obtains a first identifier based on an identifier of the second host and the network identifier, where the first identifier is used to identify a second device, a segment routing over internet protocol version 6 (SRv6) tunnel exists between the first device and the second device, the first identifier includes an indication identifier used to indicate the second device to convert a format of a packet forwarded through the SRv6 tunnel into a format of a packet forwarded through a first network virtualization over layer 3 (NVO3) tunnel. The first device sends an SRv6 packet including the first identifier and the original packet to the second device through the SRv6 tunnel.