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. And the programs transmitted by radios and TVs can be enriched while the requirements for bandwidth of uplink transmission and bandwidth of downlink transmission can be satisfied.