A multi-device lip synchronization method, wherein the method is applied to a primary device and at least one secondary device synchronously output video and audio, wherein the primary device outputs video and the at least one secondary device outputs audio, wherein the primary device is connected to the at least one secondary device through Wi-Fi, and the method comprises: receiving, by the secondary device, a Real-Time Transport Control Protocol, RTCP, packet sent by the primary device, wherein a Real-Time Transport Protocol, RTP, time stamp header field in the RTCP packet carries a program clock reference, PCR, cyclically collected by the primary device, and a Network Time Protocol, NTP, field in the RTCP packet carries a sending time point of the RTCP packet; correcting, by the secondary device, a system clock, STC, of the secondary device based on the PCR, a program clock frequency of the primary device, a program clock frequency of the secondary device, and a RTCP delay; receiving, by the secondary device based on a multicast service address and port sent by the primary device, RTPs published by the primary device, splicing the RTPs into a complete audio data frame, obtaining, from a time stamp header field of the RTP packet, a presentation time stamp, PTS, corresponding to the audio data frame, and storing the audio data frame into an audio pulse code modulation, PCM, buffer of the secondary device; and outputting, by the secondary device, the audio data frame in the audio PCM buffer based on the STC of the secondary device and the presentation time stamp of the audio data frame, wherein before the receiving, by the secondary device, a Real-Time Transport Control Protocol, RTCP, packet sent by the primary device, the method further comprises: receiving, by the secondary device, media description information sent by the primary device, wherein the media description information comprises a Simple Network Time Protocol, SNTP, service address and port, a RTCP service address and port, the multicast service address and port, the program clock frequency of the primary device, a media format, and a time stamp frequency; performing, by the secondary device, system time synchronization based on the SNTP service address and port; and the receiving, by the secondary device, a Real-Time Transport Control Protocol, RTCP, packet sent by the primary device comprises: receiving, by the secondary device based on the RTCP service address and port, the RTCP packet sent by the primary device. receiving, by the secondary device, a Real-Time Transport Control Protocol, RTCP, packet sent by the primary device, wherein a Real-Time Transport Protocol, RTP, time stamp header field in the RTCP packet carries a program clock reference, PCR, cyclically collected by the primary device, and a Network Time Protocol, NTP, field in the RTCP packet carries a sending time point of the RTCP packet; correcting, by the secondary device, a system clock, STC, of the secondary device based on the PCR, a program clock frequency of the primary device, a program clock frequency of the secondary device, and a RTCP delay; receiving, by the secondary device based on a multicast service address and port sent by the primary device, RTPs published by the primary device, splicing the RTPs into a complete audio data frame, obtaining, from a time stamp header field of the RTP packet, a presentation time stamp, PTS, corresponding to the audio data frame, and storing the audio data frame into an audio pulse code modulation, PCM, buffer of the secondary device; and outputting, by the secondary device, the audio data frame in the audio PCM buffer based on the STC of the secondary device and the presentation time stamp of the audio data frame, wherein before the receiving, by the secondary device, a Real-Time Transport Control Protocol, RTCP, packet sent by the primary device, the method further comprises: receiving, by the secondary device, media description information sent by the primary device, wherein the media description information comprises a Simple Network Time Protocol, SNTP, service address and port, a RTCP service address and port, the multicast service address and port, the program clock frequency of the primary device, a media format, and a time stamp frequency; performing, by the secondary device, system time synchronization based on the SNTP service address and port; and the receiving, by the secondary device, a Real-Time Transport Control Protocol, RTCP, packet sent by the primary device comprises: receiving, by the secondary device based on the RTCP service address and port, the RTCP packet sent by the primary device. receiving, by the secondary device, media description information sent by the primary device, wherein the media description information comprises a Simple Network Time Protocol, SNTP, service address and port, a RTCP service address and port, the multicast service address and port, the program clock frequency of the primary device, a media format, and a time stamp frequency; performing, by the secondary device, system time synchronization based on the SNTP service address and port; and the receiving, by the secondary device, a Real-Time Transport Control Protocol, RTCP, packet sent by the primary device comprises: receiving, by the secondary device based on the RTCP service address and port, the RTCP packet sent by the primary device.