A network slicing-based communication method, comprising: receiving, by a radio access network device, a registration request from a user equipment, wherein the registration request comprises first information and second information, the first information is used to indicate a type of a first network slice, and the second information is used to identify a first network slice instance in the first network slice; determining, by the radio access network device, a first access and mobility management function network element based on the type of the first network slice and the first network slice instance; sending, by the radio access network device, the registration request to the access and mobility management function network element, wherein the first information and the second information are used for network slice instance determining characterized by further comprising: receiving, by the radio access network device, capability information from another access and mobility management function network element, wherein the capability information is used to indicate a network slice type and a network slice instance that are supported by the other access and mobility management function network element; and determining, by the radio access network device, the other access and mobility management function network element based on the type of the first network slice, the first network slice instance, and the capability information; wherein the determined access and mobility management function network element supports the type of the first network slice and the first network slice instance requested by the user equipment. receiving, by a radio access network device, a registration request from a user equipment, wherein the registration request comprises first information and second information, the first information is used to indicate a type of a first network slice, and the second information is used to identify a first network slice instance in the first network slice; determining, by the radio access network device, a first access and mobility management function network element based on the type of the first network slice and the first network slice instance; sending, by the radio access network device, the registration request to the access and mobility management function network element, wherein the first information and the second information are used for network slice instance determining characterized by further comprising: receiving, by the radio access network device, capability information from another access and mobility management function network element, wherein the capability information is used to indicate a network slice type and a network slice instance that are supported by the other access and mobility management function network element; and determining, by the radio access network device, the other access and mobility management function network element based on the type of the first network slice, the first network slice instance, and the capability information; wherein the determined access and mobility management function network element supports the type of the first network slice and the first network slice instance requested by the user equipment. receiving, by the radio access network device, capability information from another access and mobility management function network element, wherein the capability information is used to indicate a network slice type and a network slice instance that are supported by the other access and mobility management function network element; and determining, by the radio access network device, the other access and mobility management function network element based on the type of the first network slice, the first network slice instance, and the capability information; wherein the determined access and mobility management function network element supports the type of the first network slice and the first network slice instance requested by the user equipment.