Flannery O’Connor is identified today as one of the most outstanding American Southern writers. Enlightened by Christianity, she treats spiritual crisis as her works’ eternal theme. She believes that writers’ responsibility is to help the readers get profound insight into humanity. The critical reviews on O’Connor’s works have focused on the religious motif and the characters’ grotesqueness, sin and salvation, etc. So far, researches have been conducted within the framework of new criticism, feminist criticism, violence aesthetics and narratology and so on. Until now, however, few Freudian psychoanalytic studies have been done to explore the internal reasons for the characters’ grotesqueness and the author’s writing motivations. So this paper applies such Freudian concepts as libido, defense mechanisms and life- and death instinct to interpret the protagonist in O’Connor’s “Good Country People”, in an attempt to shed light on Hulga’s actions and minds as well as the author’s motivations. Moreover, the integration of Freudian psychoanalysis into the social background and the author’s experiences provides us with a new perspective to scrutinize the inner nature of O’Connor and her fictional figures.