A method for obtaining a noise power and a terminal are provided. The obtaining method includes: obtaining a first power offset value of an actual automatic gain control (AGC) received power relative to a first predetermined received power within a predetermined transmission time interval (TTI); obtaining, according to a preset correspondence between a modulation mode and an AGC backoff value, a target AGC backoff value corresponding to a current modulation mode; and obtaining the noise power according to the first power offset value, the target AGC backoff value, and a current AGC received power.