A data center network system, comprising one hub device, at least two switches, multiple colored optical modules, at least two multiplexers/demultiplexers, and at least two servers, wherein there is a communication connection between at least one of the at least two switches and at least one server, and there are communication connections between different input/output ports of each switch and different colored optical modules; there are communication connections between the different colored optical modules that have communication connections to the different input/output ports of each switch and one multiplexer/demultiplexer, wherein different switches are communicatively connected to different multiplexers/demultiplexers by using colored optical modules; the at least two switches and the hub device form a star network topology structure by using the multiplexers/demultiplexers, wherein the hub device is separately communicatively connected to different multiplexers/demultiplexers by using different ports; the switch is configured to: receive at least two electrical signals, and separately process each of the at least two electrical signals according to the following processing manner for a first electrical signal: determining an input/output port corresponding to a destination address carried in the first electrical signal, and outputting the first electrical signal by using the determined input/output port, wherein the destination address is used to indicate a destination server; the input/output port corresponding to the destination address is an input/output port corresponding to a destination switch that is communicatively connected to the destination server; the destination server is one of the at least two servers; the destination switch is a switch that is communicatively connected to the destination server; and the at least two electrical signals comprise any one or a combination of the following: electrical signals sent by a server that has a communication connection to the switch, or electrical signals from another switch in the at least two switches; the colored optical module is configured to: receive an electrical signal output by an input/output port of a switch that has a communication connection to the colored optical module, and convert the received electrical signal into an optical signal with a specific wavelength, wherein optical signals obtained through conversion by different colored optical modules that have communication connections to different input/output ports of a switch have different wavelengths; the multiplexer/demultiplexer is configured to: receive multiple optical signals sent by each of multiple colored optical modules that have communication connections to the multiplexer/demultiplexer, and perform wavelength division multiplexing on the multiple optical signals to form a combined signal; the hub device is configured to: receive the combined signal sent by the multiplexer/demultiplexer, demultiplex the combined signal to obtain multiple optical signals, send each of the multiple optical signals to a port corresponding to a destination switch of the optical signal, output each optical signal from the corresponding port, and perform wavelength division multiplexing on optical signals output from a same port to form a combined signal; the multiplexer/demultiplexer is further configured to: receive the combined signal from the hub device, demultiplex the combined signal to obtain multiple optical signals, and separately input the multiple optical signals to colored optical modules corresponding to wavelengths of the optical signals; the colored optical module is further configured to: receive an optical signal from the multiplexer/demultiplexer, convert the optical signal into an electrical signal, and output the electrical signal to an input/output port of a switch that has a communication connection to the colored optical module; and the switch is further configured to forward the electrical signal received from the colored optical module to a destination server of the electrical signal.