Embodiments of this application provide a hyper system frame number determining method, a communication method and apparatus. The method includes the following steps. First, determining, by an access network device, a first hyper system frame number (HSFN) and a first system frame number SFN, where the first HSFN and the first SFN are determined by the access network device based on a time at which enhanced discontinuous reception (eDRX) is enabled and a preconfigured time. Second, determining, by the access network device, an HSFN adjustment value based on the first SFN and a second SFN, where the second SFN is an SFN used at the time at which the access network device enables the eDRX. Third, adjusting, by the access network device, the first HSFN to a second HSFN based on the HSFN adjustment value, and updating the second HSFN based on the second SFN.