Embodiments disclose a multiple-communications-standard transmission method and apparatus. The method includes when both a WLAN communications standard and a wireless cellular communications standard are available, sending, by a transmit end supporting multiple communications standards by preferentially using the WLAN communications standard, a service flow of a service session to a receive end supporting multiple communications standards. The method also includes in response to that a first switch condition is met, switching, by the transmit end at a data link layer, to using the wireless cellular communications standard for continuous transmission of the service flow, where the first switch condition includes at least that a WLAN communication link fails in communication.