Psychosexual disorders, formerly referred to as “sexual perversions”, are a group of psychological disorders characterized by obvious deviations from normal sexual psychology and sexual behavior, and characterized by such deviations as the only or the main way of sexual arousal and sexual satisfaction. Generally, there is no obvious abnormality in mental activities, except for the normal sexual psychology which is seriously affected and damaged. Human sexual behavior from normal to abnormal can be seen as a continuous spectrum, during which there are different degrees of excessive forms, if they do not form damage and influence on their own sexual psychology, can be seen as normal variant forms, and not considered as sexual psychological disorders. Human sexual behavior is influenced and regulated by social culture, and different countries, nationalities and religious beliefs may have different moral standards and values on sexual psychology and sexual behavior, so there is no absolute standard to determine whether the sexual psychology is normal or not. However, the following two items can be identified: ① Is it accepted by the public in the society? ② Does it cause damage and pain to oneself or to one’s sexual partner? In terms of clinical manifestations, there are three main types of psychosexual disorders: sexual identity disorder (referring to transsexualism), sexual preference disorder (referring to sexual perversions other than transsexualism and homosexuality), and sexual orientation disorder (referring to homosexuality and bipolarity). Sexual identity disorders are individuals whose internal beliefs about gender identity do not correspond to their biological sex and include transsexualism, dual cross-dressing disorder, and childhood sexual identity disorder. There are many types of sexual preference disorders, all of which are less common and are often discovered because of multiple infractions. Sexual preference disorders can be divided into two categories, sexual object abnormalities and sexual action variants. Its development is related to human gonadal activity, which generally begins to be evident in adolescence and becomes evident in old age, especially near menopause, as gonadal activity tends to decline and behavior tends to moderate. Many forms of sexual preference and behavior disorders are present, including: fetishism, fetish transvestism, exhibitionism, rubism, voyeurism, bestiality, pedophilia, sadomasochism, and necrophilia. Patients with psychosexual disorders may often violate social norms, and some even violate the law, to be carefully diagnosed and identified, should not be generalized that they are morally corrupt, not to mention equal to sexual crimes.