Combining epidural with general anesthesia is regarded as the gold standard of general thoracic surgery. The uniportal VATS lung surgery have advantages of minimal invasive surgical incision, less postoperative pain, and so on. Whether general anesthesia can become an alternative method of combining epidural with general anesthesia in uniportal VATS lung surgery, investigators thus plan to make a comparison on intraoperative stress response, postoperative pain, immune function of patients，and hospital expenses.