Abstract: The present disclosure relates to a multimedia network data processing system, comprising: a head-end switch, which transmits multimedia network data of the data that is sent from a server to a terminal device to a head-end network processor, wherein the multimedia network data is multimedia network data based on the TCP/HTTP protocol; a head-end network processor, which encapsulates the multimedia network data to form a UDP packet and sends the UDP packet to a unidirectional broadcasting optical fiber network; and a data processing module, which receives the UDP packet from the unidirectional broadcasting optical fiber network and decapsulates the UDP packet to obtain the multimedia network data based on the TCP/HTTP protocol for the terminal device to play. A video-on-demand service based on the TCP/HTTP protocol can be realized on the basis of the existing network systems in which the unidirectional channel and the bidirectional channel are separated.