The present invention relates to the technical field of wireless communications. Disclosed are a physical cell identifier allocation method and an apparatus. In a scheme, when allocating a physical cell identifier, first determining a degree of interference of each type of an adjacent cell to a main cell for which a physical cell identifier needs to be allocated, and then performing allocation for the main cell based on a remainder value corresponding to a minimum degree of interference, thus implementing effective reduction of reference signal interference and improving effectiveness of reducing reference signal interference.