Childhood trauma is associated with the recovery and prognosis of depressive disorder. It is believed that the occurrence of depressive disorder accompanied by childhood trauma is the result of the interaction between genes and environment， and non-homogeneous neurobiological mechanisms are also involved. Gene polymorphism， also known as genetic polymorphism， refers to the simultaneous or frequent presence of two or more discontinuous variations in a population of organisms. Research has found that childhood trauma and depressive disorder may be associated with gene polymorphisms in the neurotransmitter system， hypothalamic-pituitary-adrenal axis， brain-derived neurotrophic factor， and inflammation. This article reviews candidate gene polymorphisms related to depressive disorder， aiming to reveal the potential pathogenesis of depressive disorder patients with childhood trauma and provide theoretical basis for early diagnosis and treatment of depressive disorder.