This application provides an access control apparatus and method, and an access apparatus and method. The access control apparatus includes: a receiving unit, configured to receive a first preamble sequence; a determining unit, configured to determine an acquired-terminal group; and a sending unit, configured to send a first acquisition indicator; where the receiving unit is further configured to receive a second preamble sequence, the determining unit is further configured to determine an acquired terminal, and the sending unit is further configured to send a second acquisition indicator, where the second acquisition indicator is used to indicate access of the acquired terminal. In the present invention, a process of contending for an access resource by a terminal transforms from one-phase contention to two-phase contention, so that a quantity of preamble sequences received by the base station each time can be greatly reduced, thereby effectively reducing load of the base station.