A frequency domain resource adjustment method, wherein the method comprises: receiving, by a terminal device, information about a guard time from a network device, the guard time being a period of time during which the terminal device is configured to change a frequency domain resource for communication of the terminal device; determining, by the terminal device, the guard time based on the information about the guard time; and adjusting, by the terminal device, a first frequency domain resource to a second frequency domain resource within the guard time, wherein the method further comprises: receiving, by the terminal device, indication information from the network device, wherein the indication information is used to instruct the terminal device to adjust a frequency domain resource to the second frequency domain resource; and the adjusting, by the terminal device, a first frequency domain resource to a second frequency domain resource within the guard time comprises: adjusting, by the terminal device, the first frequency domain resource to the second frequency domain resource within the guard time based on the indication information, and wherein the method further comprises: receiving, by the terminal device, first configuration information from the network device, wherein the first configuration information comprises at least one frequency domain resource adjustment combination, and the indication information is used to indicate one frequency domain resource adjustment combination in the first configuration information. receiving, by a terminal device, information about a guard time from a network device, the guard time being a period of time during which the terminal device is configured to change a frequency domain resource for communication of the terminal device; determining, by the terminal device, the guard time based on the information about the guard time; and adjusting, by the terminal device, a first frequency domain resource to a second frequency domain resource within the guard time, wherein the method further comprises: receiving, by the terminal device, indication information from the network device, wherein the indication information is used to instruct the terminal device to adjust a frequency domain resource to the second frequency domain resource; and the adjusting, by the terminal device, a first frequency domain resource to a second frequency domain resource within the guard time comprises: adjusting, by the terminal device, the first frequency domain resource to the second frequency domain resource within the guard time based on the indication information, and wherein the method further comprises: receiving, by the terminal device, first configuration information from the network device, wherein the first configuration information comprises at least one frequency domain resource adjustment combination, and the indication information is used to indicate one frequency domain resource adjustment combination in the first configuration information. receiving, by the terminal device, indication information from the network device, wherein the indication information is used to instruct the terminal device to adjust a frequency domain resource to the second frequency domain resource; and the adjusting, by the terminal device, a first frequency domain resource to a second frequency domain resource within the guard time comprises: adjusting, by the terminal device, the first frequency domain resource to the second frequency domain resource within the guard time based on the indication information, and wherein the method further comprises: receiving, by the terminal device, first configuration information from the network device, wherein the first configuration information comprises at least one frequency domain resource adjustment combination, and the indication information is used to indicate one frequency domain resource adjustment combination in the first configuration information. adjusting, by the terminal device, the first frequency domain resource to the second frequency domain resource within the guard time based on the indication information, and wherein the method further comprises: receiving, by the terminal device, first configuration information from the network device, wherein the first configuration information comprises at least one frequency domain resource adjustment combination, and the indication information is used to indicate one frequency domain resource adjustment combination in the first configuration information.