Abstract: Poststroke depression is a common complication after stroke, which has a profound impact on the prognosis of stroke patients. The article introduced the origin of the depression caused by stagnation theory. The pathogenesis connotation of the theory mainly includes two points: cerebral collateral stasis leading to vital activity dysfunction; nourishment deprivation of heart spirit leading to depression. The article also explored the modern biological mechanisms of depression caused by stagnation as well as poststroke depression. It is believed that the pathological mechanism of poststroke depression is closely related to factors such as low cerebral blood flow, platelet dysfunction, endothelial dysfunction, abnormal lipid metabolism, and inflammatory response. From the perspective of the joint treatment of body and spirit, it is proposed that the treatment of poststroke depression should mainly focus on promoting blood circulation and relieving depression. It is not only necessary to treat the stroke itself, but also to pay attention to the identification and intervention of psychological disorders caused by the disease.