Depression and anxiety are psychological disorders that include physical, emotional and social factors, which are widely seen in the diagnosis and treatment of patients with malignant tumors. Colorectal malignancy is one of the common malignant tumors in China. At present, the treatment mode is a multidisciplinary comprehensive treatment mode with surgery as the main treatment and radiotherapy, chemotherapy and targeted therapy as the supplement. However, surgery, radiotherapy and chemotherapy can aggravate the negative emotions of patients, and lead to the occurrence of anxiety and depression. Anxiety and depression in patients with malignant tumors often manifest as despair, helplessness, panic, etc., which will not only complicate the treatment due to reduced patient compliance, but also reduce patients' immune function, accelerate disease progression, directly affect patients' quality of life and increase mortality. Positive psychological intervention can effectively improve the above problems caused by anxiety and depression. Research on anxiety and depression and psychological intervention are expected to improve the prognosis of patients with malignant tumors.