This application provide a resource indication method and a related device. According to the method provided in this application, a terminal device can send a HARQ-ACK on a PUCCH resource in at least one sub-slot. The resource indication method may be applied to the terminal device. The method may include: The terminal device may receive DCI from a network device, where the DCI indicates a slot used by the terminal device to transmit a HARQ-ACK. After receiving the DCI, the terminal device may send the HARQ-ACK on a PUCCH resource in at least one sub-slot of the slot indicated by the DCI. The slot includes at least two sub-slots. In other words, the terminal device may send the HARQ-ACK on a PUCCH resource in one sub-slot of the slot, or may send the HARQ-ACK on a PUCCH resource in a plurality of sub-slots of the slot.