In conclusion, this dissertation analyzes the image of Snape from the negative, positive and paradoxical aspects on the basis of Freud's id, ego and superego psychanalysis theory. Snape is an image of great complexity and unpredictability, his life experience builds his personality and his personality reversely determines his path of life. Readers obtain great reading enjoyment on such attractive role and Snape enhances the readability of the“Harry Potter”series.