Written by Ian McEwan,The Children Act which was published in 2014 is a novel that reflects the conflicts between religion and law,sense and sensibility.By using Freud’s theory of personality structure,what Fiona really want hidden behind her extreme rationality will be found and the author also intends to seek a good way to go out of the dilemma for individuals in mod?ern society.First of all,it will analyze Fiona’s dilemma,including her dilemma in the marriage crisis and occupation,in which it will analyze the contest of“Id”,“Ego”and“Superego”behind her choice.By analyzing from this perspective,the author wants to find out the reasons behind Fiona’s choice and behavior.Additionally,it will analyze Fiona’s epiphany after death of Adam,including epiphany of the children’s welfare and that of her emotion.