What is the effect of lymph node dissection on human body should be analyzed objectively based on factors such as whether lymph node lesions occur. Lymph nodes are very important immune organs of human body. If there is no serious lesion in lymph nodes, lymph node dissection on a large scale at this time will cause a significant decrease in immunity of the body and serious bacterial and viral infections, causing serious complications. If septic infection occurs in lymph nodes, surgical excision of infected lymph nodes at this time can avoid progressive aggravation of local infection, promote faster recovery of patient’s condition and achieve better treatment effect. In patients with malignant tumors, lymph nodes with extensive invasion are often found during surgery, and lymph node dissection at this time may remove tumor cells in patients, but excessive lymph node dissection may cause lymphatic leakage after surgery and cause serious infection in the abdominal cavity.