A broadband communication network architecture with a train control network and a train serving network combined, is characterized by, comprising a trusted network and an untrusted network; the trusted network comprises a trusted carriage-level network element provided in each carriage, and in each of a front carriage and a last carriage, in addition to the trusted carriage-level network element, a trusted train-level network element is provided; the untrusted network comprises untrusted train-level network elements respectively provided in the front carriage and the last carriage; one trusted train-level network element communicates with one untrusted train-level network element via a security gateway, and several security gateways are redundant to each other. The network architecture of the present application is a broadband communication network architecture combining a train control network and a train serving network, by which the train control information, the monitored information and the diagnostic information, as well as the passenger information and the video information can be transmitted in a combined network, i.e., the transmission of the data from the passenger information serving system network and the data from the train control network in a combined network, thereby meeting a demand for a bandwidth of the passenger information serving system network and ensuring a stability of the train network.