Embodiments disclose a resource assignment method and a device. The method includes determining a first downlink subframe set, where the first downlink subframe set is associated with a first uplink subframe in both a first uplink-downlink configuration and a second uplink-downlink configuration; and determining, in the first uplink subframe, a first PUCCH resource region according to HARQ timing of the first uplink-downlink configuration, where the first PUCCH resource region is a resource region reserved for HARQ feedback information for the first downlink subframe set. A quantity and sequence numbers of elements under a first uplink-downlink configuration is used for all downlink subframes in a first downlink subframe set of later-released UE, so that a same first PUCCH resource region is assigned, so as to implement assignment of a PUCCH resource region to the later-released UE in a system compatible with two types of UEs.