This application provides a data transmission method and an apparatus, in which two radio access network devices share a resource. A first radio access network device determines a resource occupation status corresponding to a different status of a second access network device on a shared resource. The first radio access network device indicates the resource occupation status to a terminal device served by the first radio access network device. The terminal device determines an available resource in a shared carrier based on the resource occupation status, and communicates with the first access network device using the available resource. The first radio access network device can perform communication on the shared resource regardless of a status of the second radio access network device on the shared resource, so that the two radio access network devices flexibly and efficiently coexist in the shared carrier. This improves utilization of the shared resource.