Objective To investigate the applied significance of adjustable low-concentration of mixed oxygenand nitrous oxide inhalation sedation combined with lidocaine local anesthesia in anorectal surgery. Methods Three hundreds patients underwent anorectal surgery in our hospital were divided into control group （n=154） and observation group （n=146）. Patients of control group underwent pure lidocaine local anesthesia， and patients of observation group underwent mixed oxygen and nitrous oxide sedation analgesia combined with lidocaine local anesthesia. Vital signs before and after operation as well as results of sedation and analgesia were compared between the 2 groups. Results Anorectal surgeries of all patients were performed successfully. There were no significant differences on change of heart rate， blood pressure， and oxygen saturation between the 2 groups before and after operation （P＞0.05）. The operation time between the control group 〔（36.3±6.8） min〕 and observation group 〔（35.4±6.5） min〕 had no statistically significant difference（t=-0.607， P=0.544）. The analgesic effects （Z=-6.859， P=0.000） and sedative effects （Z=-5.275， P=0.000） of obser-vation group were both better than those of control group. Conclusions Low-concentration of mixed oxygen and nitrous oxide inhalation sedation combined with lidocaine local anesthesia can relieve the discomfort of fear and pain， no side-impacts on vital sign before and after operation were observed，and it has better effects of sedation and analgesia， therefore it can be recommended to clinical application.