A system for processing a streaming media service and a method and a network device thereof are provided. The system includes a network device and an encoder. The network device has an embedded streaming function module. The encoder includes two egress ports, where the two egress ports of the encoder are connected to an active input port and a standby input port of the network device respectively. The encoder is configured to: receive a streaming media service signal, encode the streaming media service signal to generate a streaming media service coded signal, and send the streaming media service coded signal to the network device. The network device is configured to receive, by using the embedded streaming function module through the active input port or the standby input port, a streaming media service coded signal sent by the encoder, and provide the streaming media service coded signal for a terminal.