Embodiments of this application provide a communication method and a related device. The method includes: A terminal device obtains a plurality of power offset values corresponding to one reference signal resource, determines a plurality of pieces of channel state information CSI based on the plurality of offset values, and sends some or all of the plurality of pieces of CSI to a network device. The network device may flexibly adjust data transmit power based on the plurality of power offset values and the plurality of pieces of corresponding CSI, and perform appropriate link adaptation adjustment.