Embodiments of this application provide a communication method and a device, and relate to the field of communication technologies. An example solution is as follows: determining, by a communications device, a quantity of physical downlink shared channels PDSCHs based on a value set of K1 and a time domain resource allocation table; determining, by the communications device, a quantity of physical downlink control channels (PDCCHs) based on the value set of K1, a value of K0 in the time domain resource allocation table, a PDCCH period, a PDCCH monitor offset, and a PDCCH monitor pattern; and determining, by the communications device, a HARQ codebook based on the quantity of PDSCHs and the quantity of PDCCHs.