The embodiment of the invention discloses a data communication method. The method comprises following steps of determining an idle channel by a first terminal; sending a data handshake request carrying with interruption information on the idle channel, wherein the interruption information at least comprises an instruction of interrupting the call of a service channel; receiving a data handshake response sent by a relay station; skipping to the service channel appointed by the relay station according to the skip channel instruction contained in the data handshake response when the type of the data handshake response is the data handshake response of allowing interruption; initiating the call on the service channel when it is determined that a second terminal which occupies the service channel to carry out the call interrupts the call, and the resource of the service channel is released. According to the embodiment of the invention, the call of the sending terminal can be interrupted, the channel resource can be released, and the method, the device and the system are high in flexibility and efficiency.