Based on Freud’s theory of personality structure, this paper discussed the causes of Jake Barnes’ love tragedy in The Sun Also Rises from the three perspectives, namely, id, ego and superego as well as the conflicts and imbalances in the three perspectives. The behaviors and psychological changes of the protagonist Jake in different periods from the above perspectives were analyzed in detail, showing that Jake had experienced a psychological process of indulging himself in the primitive desires, trying to redeem himself and in vain. A conclusion was drawn that Jake’s disillusionment of superego projection and excessive repression of ego jointly led to the tragedy of his love.