First of all, the immunity of the body is lower after gastric cancer surgery, especially the function of the lungs will be affected to a certain extent, if you smoke too much at this time, it will stimulate the mucous membrane of the respiratory tract, which may lead to bronchopneumonia or cough and sputum, and it is easy for secondary infection. It is also very unfavorable to the recovery of stomach cancer surgery. In addition, nicotine and harmful substances in smoke have potential risks for incision and intestinal function recovery after gastric cancer surgery. Therefore, it is important to quit smoking, limit alcohol and avoid smoking after gastric cancer surgery so as to effectively recover from the surgery and then carry out the corresponding radiotherapy, chemotherapy or neoadjuvant therapy.