Device, method and system for treating AT command

The invention discloses device, method and system for treating an AT command, wherein the device for treating the AT command comprises an AT command sending module and an AT command receiving module, wherein the AT command sending module is used for receiving business information from a terminal module and calling application functions so as to send AT channel application information to the AT command receiving module; and the AT command receiving module opens a channel used for transferring the AT command and receiving AT command response information between the AT command sending module and the AT command receiving module according to the AT channel application information, closes the AT channel, sends the AT command to a data conversion module and receives the AT command response information from the data conversion module. The system thereof is added with the AT command sending module and the AT command receiving module, can be provided with a plurality of AT channels in parallel, supports intercurrent multi-business of the terminal module and closes the AT channels after business is finished, thereby saving large channel resources.