This application provides a data transmission method and a related apparatus. The method includes: A network device generates a first physical layer protocol data unit PPDU. The first PPDU includes a first universal-Signaling field U-SIG field and a first extremely high throughput-Signaling field EHT-SIG field, a sum of a quantity of information bits of the first U-SIG field and a quantity of information bits of the first EHT-SIG field is less than or equal to 78 information bits, and at least one of the first U-SIG field and the first EHT-SIG field includes an identifier indication field, where the identifier indication field is used to uniquely identify one station. The network device sends an encoded first PPDU to a station.