A data terminal, comprising: a first processor, a first digital audio circuit, an interface isolator, a first universal serial bus USB circuit, and a first connecting apparatus, wherein the first connecting apparatus comprises a first digital audio connecting apparatus and a first USB connecting apparatus, and the first USB circuit has a hot swapping feature; the first processor is connected to the first digital audio circuit, the first processor is further connected to the first USB circuit, the first digital audio circuit is connected to the interface isolator, the interface isolator is connected to the first digital audio connecting apparatus, and the first USB circuit is connected to the first USB connecting apparatus; after the data terminal is connected to a computer by using the first connecting apparatus, an initial status of the interface isolator is a disconnected state and the first USB circuit enters an initialization process; the first processor is configured to: after initialization of the first USB circuit is complete, negotiate with the computer by using the first USB circuit and the first USB connecting apparatus, determine a first configuration parameter of the first digital audio circuit, and configure the first digital audio circuit according to the first configuration parameter; and after configuration on the first digital audio circuit is complete, the interface isolator receives a connection command, and switches from the disconnected state to a connected state according to the connection command, so that a channel between the first digital audio circuit and the first digital audio connecting apparatus is connected, and voice data transmission is performed between the first processor and the computer by using the first digital audio circuit and the first digital audio connecting apparatus. a first processor, a first digital audio circuit, an interface isolator, a first universal serial bus USB circuit, and a first connecting apparatus, wherein the first connecting apparatus comprises a first digital audio connecting apparatus and a first USB connecting apparatus, and the first USB circuit has a hot swapping feature; the first processor is connected to the first digital audio circuit, the first processor is further connected to the first USB circuit, the first digital audio circuit is connected to the interface isolator, the interface isolator is connected to the first digital audio connecting apparatus, and the first USB circuit is connected to the first USB connecting apparatus; after the data terminal is connected to a computer by using the first connecting apparatus, an initial status of the interface isolator is a disconnected state and the first USB circuit enters an initialization process; the first processor is configured to: after initialization of the first USB circuit is complete, negotiate with the computer by using the first USB circuit and the first USB connecting apparatus, determine a first configuration parameter of the first digital audio circuit, and configure the first digital audio circuit according to the first configuration parameter; and after configuration on the first digital audio circuit is complete, the interface isolator receives a connection command, and switches from the disconnected state to a connected state according to the connection command, so that a channel between the first digital audio circuit and the first digital audio connecting apparatus is connected, and voice data transmission is performed between the first processor and the computer by using the first digital audio circuit and the first digital audio connecting apparatus.