A quality of service (QoS) parameter processing method and a system, where the method includes obtaining, by a control plane device, a core network (CN) packet delay budget (PDB) between a first access network device and a first user plane function device, sending, by the control plane device, the CN PDB to the first access network device, determining, by the first access network device, an access network (AN) PDB between a terminal device and the first access network device based on the CN PDB and an end-to-end PDB between the terminal device and the first user plane function device, and scheduling, by the first access network device, an air interface resource between the terminal device and the first access network device based on the AN PDB.