Sexual minorities, including lesbian, gay, bisexual and transgender, are under pressure from more sources and need counseling. Affirmative psychotherapy and counseling is more culturally appropriate for psychological counseling for sexual minorities, and is constructed on the basis of the combination of traditional psychological counseling theory and other related theories. The application of affirmative psychotherapy and counseling to school practice is of positive significance to the mental health of teachers and students, the construction of excellent campus culture and the school counseling of sexual minorities. To train LGBT-affirmative counselors in schools should pay attention to attitudes and beliefs about different sexual orientations and gender identities, acquire relevant knowledge of sexual minorities, and understand the particularity of school counseling. The school practice of affirmative psychotherapy and counseling should also pay attention to the evaluation of training and consultation effect, the Chinese cultural background, the independent construction of the school counseling and the integration of campus activities.