Provided are an information transmission method, a resource allocation method, a terminal device, and a network device. In embodiments of the present invention, a terminal device converts at least one first carrier corresponding to a first address into at least one first carrier corresponding to a first index, converts at least one second carrier corresponding to a second address into at least one second carrier corresponding to a second index, and report the at least one first carrier corresponding to the first index and the at least one second carrier corresponding to the second index to a network device, so that the network device can determine at least one first carrier corresponding to a first address according to the first index and at least one second carrier corresponding to a second address according to the second index.