This application discloses a directional measurement method and a device. In this solution, a terminal device may determine a to-be-measured receive beam, and perform RSSI measurement on the to-be-measured receive beam. According to the method, the terminal device may perform RSSI measurement on the to-be-measured receive beam in a targeted manner, and does not need to perform RSSI measurement in all directions. Therefore, in the method, directional RSSI measurement of the terminal device can be implemented, time and power that are consumed by the terminal device to perform RSSI measurement can be reduced, and RSSI measurement efficiency of the terminal device can be improved.