The invention discloses a video frame structure and D2D (Device-to-Device) communication based 
video multicast method. The video frame structure and D2D communication based 
video multicast method comprises steps that a 
base station announces a 
video multicast service, and all the interested users in a 
cell join in the service to form a 
multicast cluster; the 
base station carries out video 
stream multicast for the users in the cluster by regarding the 
transmission time of one basic unit GOP (
Group of Pictures) in a video code as a cycle; the users check received information and report sequence numbers of frames having 
packet loss in the GOP to the 
base station after the 
multicast sub time slot is ended; the base 
station after receiving feedback information of the users establishes a sequence 
list based on the priorities of to-be-restored frames and establishes a CQI matrix of a D2D link between target frames ACK-devices and NACK-devices; 
relay selection and grouping are performed based on the CQI matrix and the time Tm required for transmission of the target frame m is calculated; and after the transmission is finished, the sequence number of the current target frame in the sequence 
list is deleted. The video frame structure and D2D communication based video multicast method efficiently overcomes the problem that the multicast rate in the 
multimedia multicast is always affected by the worst 
fading channel in the cluster, and greatly improves the 
video quality within limited spectrum resources from the perspective of the user.