Depression is a complex clinical disease， in addition to their own emotional changes， the perception of pain will also change significantly. Clinically， it is often reported that the pain threshold of depressed patients is increased， and antidepressants will also affect the pain threshold on the basis of the original treatment of depression. Due to the complexity of pathophysiology， the current conclusions on the influence and mechanism of depression and antidepressants on pain threshold are still relatively superficial， but the neural mechanism of the cerebral cortex and brainstem behind the pain threshold has been innovated in recent years. This article reviews the different effects and potential mechanisms of depression and antidepressant drugs on pain threshold， and discusses the potential neural mechanisms of pain transmission and regulation from the aspects of receptors and transmitters in the brain， brainstem and spinal cord， aiming to provide new ideas for the study and clinical treatment of the mechanism of pain threshold change in patients with depression.