A communication method, comprising: obtaining (S210, S310), by a first network device, service usage of a first network slice and a service usage threshold of the first network slice, from another network device other than a second network device; generating (S220, S320), by the first network device, indication information based on the service usage of the first network slice and the service usage threshold of the first network slice; and sending (S230, S330), by the first network device, the indication information to the second network device, wherein the indication information is used for controlling resource pre-emption at the second network device; wherein the service usage threshold of the first network slice comprises an upper service usage limit of the first network slice and a lower service usage limit of the first network slice; and if the service usage of the first network slice is greater than or equal to the upper service usage limit of the first network slice, the indication information indicates the second network device to release, for first service data that is to access the first network slice, a resource for service data that has accessed the first network slice, or the indication information indicates that allowed service usage of the first network slice is greater than or equal to the upper service usage limit of the first network slice, if the service usage of the first network slice is less than or equal to the lower service usage limit of the first network slice, the indication information indicates that a resource for any piece of service data that has accessed the first network slice is not pre-empted by any piece of service data that is to access a second network slice, or the indication information indicates that the service usage of the first network slice is less than or equal to the lower service usage limit of the first network slice. obtaining (S210, S310), by a first network device, service usage of a first network slice and a service usage threshold of the first network slice, from another network device other than a second network device; generating (S220, S320), by the first network device, indication information based on the service usage of the first network slice and the service usage threshold of the first network slice; and sending (S230, S330), by the first network device, the indication information to the second network device, wherein the indication information is used for controlling resource pre-emption at the second network device; wherein the service usage threshold of the first network slice comprises an upper service usage limit of the first network slice and a lower service usage limit of the first network slice; and if the service usage of the first network slice is greater than or equal to the upper service usage limit of the first network slice, the indication information indicates the second network device to release, for first service data that is to access the first network slice, a resource for service data that has accessed the first network slice, or the indication information indicates that allowed service usage of the first network slice is greater than or equal to the upper service usage limit of the first network slice, if the service usage of the first network slice is less than or equal to the lower service usage limit of the first network slice, the indication information indicates that a resource for any piece of service data that has accessed the first network slice is not pre-empted by any piece of service data that is to access a second network slice, or the indication information indicates that the service usage of the first network slice is less than or equal to the lower service usage limit of the first network slice.