A cell radio network temporary identifier (C-RNTI) allocation method and device are disclosed. The method includes: when UE accesses a serving cell, randomly determining, by an entity at which the serving cell is located, a start position for selecting a C-RNTI, selecting a C-RNTI for the UE within a C-RNTI interval range starting from the start position, and allocating the selected C-RNTI to the UE. So the entity at which the serving cell is located randomizes the start position of allocation performed by the entity and uses the start position as a start position of an allocation interval, so that allocation of the C-RNTI is randomized.