This application relates to the field of communications technologies, and in particular, to a management and dispatching apparatus, system and method based on a SAS. The apparatus communicates with a device in a SAS domain based on an upper-layer protocol request. A list management module manages, in a manner of a list, pending input and output information and device information that are obtained based on the upper-layer protocol request. After there is an idle SAS channel, the apparatus obtains the pending input and output information and the device information in the list by indexing the list. A DMAC on the SAS channel performs frame interaction with a corresponding device in the SAS domain based on the pending input and output information and the device information. In this application, a pending task is managed by using a list, and centralized dispatching is implemented, thereby reducing internal resource overheads.