The application provides methods for transmitting and receiving Downlink Control Information (DCI), and a related device. The receiving method includes: determining configuration information of to-be-transmitted DCI, based on a corresponding relationship between a DCI Aggregation Level (AL), and/or, a number of blind detections corresponding to the AL, and a payload size of the DCI; configuring the to-be-transmitted DCI, by using the configuration information; and, transmitting the to-be-transmitted DCI to a mobile communication terminal.