The works of Ian McEwan are mostly related to violence and ethics, which once brought him the nickname Ian Macabre. Atonement is the ninth work of McEwan. It unfolds through Briony’s sin and atonement. This paper is a brief review of Briony in different periods in the Atonement from the perspective of Sigmund Freud’s Psychoanalysis. It aims to interpret Briony’s image from Freud’s Ego, Id and Superego. To provide reader a new understanding of this novel.