Packet transmission method and apparatus

Embodiment of the present invention provides a packet transmission method and apparatus relates to the field of communications, the method comprising: receiving an authentication request from the first user device, according to the first user identifier, a first user to the home subscriber server HSS sends a user authentication request bound, such that the first user's IMSI HSS determines the binding relationship between the first user device and the first user identity is legal according to the binding relationship between the user identity and the IMSI stored; if the second a binding relationship between the user's IMSI HSS determines the first user device and the first legitimate subscriber identity, IMSI download the binding relationship between the first user device and the first user identifier of the first user from HSS and after establishing communication with the first user and the second user equipment device, when receiving a message from the first user device, the download of packets matching a binding relationship is sent to the second user device. The present invention prevents a user identity falsification occurred during data transmission, to improve the security of data transmission.