An in-ear active noise reduction earphone includes a housing, and the housing includes a rear chamber and a front chamber, and the housing is laterally provided with a sound generating unit separating the rear chamber from the front chamber; the rear chamber is located at a top of the housing, a feedforward microphone is installed inside the rear chamber, the front chamber is located at a bottom of the housing, and a feedback microphone is installed inside the front chamber; and the front chamber includes a first front chamber and a second front chamber, and the feedback microphone is installed inside the second front chamber.