A communication method performed by a first network device, the method comprising the steps of: • obtaining one or more priorities of one or more network slices in a first network slice set for providing a service to an application, wherein the application is one of a video application, a voice application, or a payment application, wherein the obtaining the one or more priorities of the one or more network slices in the first network slice set for providing the service to the application comprises: ∘ obtaining a service experience of a first network slice currently serving the application, wherein the service experience of the first network slice is expressed in terms of: ▪ if the application is the video application, a video mean opinion score, VMOS, ▪ if the application is the voice application, a mean opinion score, MOS, and ▪ if the application is the payment application, a delay in a process in which the respective terminal uses the payment application, and ∘ obtaining the one or more priorities if the service experience is less than or equal to a service experience threshold; and • sending a correspondence between the one or more priorities and the one or more network slices in the first network slice set to a second network device, wherein the correspondence is used to update a terminal route selection policy on a terminal. • obtaining one or more priorities of one or more network slices in a first network slice set for providing a service to an application, wherein the application is one of a video application, a voice application, or a payment application, wherein the obtaining the one or more priorities of the one or more network slices in the first network slice set for providing the service to the application comprises: ∘ obtaining a service experience of a first network slice currently serving the application, wherein the service experience of the first network slice is expressed in terms of: ▪ if the application is the video application, a video mean opinion score, VMOS, ▪ if the application is the voice application, a mean opinion score, MOS, and ▪ if the application is the payment application, a delay in a process in which the respective terminal uses the payment application, and ∘ obtaining the one or more priorities if the service experience is less than or equal to a service experience threshold; and ∘ obtaining a service experience of a first network slice currently serving the application, wherein the service experience of the first network slice is expressed in terms of: ▪ if the application is the video application, a video mean opinion score, VMOS, ▪ if the application is the voice application, a mean opinion score, MOS, and ▪ if the application is the payment application, a delay in a process in which the respective terminal uses the payment application, and ▪ if the application is the video application, a video mean opinion score, VMOS, ▪ if the application is the voice application, a mean opinion score, MOS, and ▪ if the application is the payment application, a delay in a process in which the respective terminal uses the payment application, and ∘ obtaining the one or more priorities if the service experience is less than or equal to a service experience threshold; and • sending a correspondence between the one or more priorities and the one or more network slices in the first network slice set to a second network device, wherein the correspondence is used to update a terminal route selection policy on a terminal.