Objective To investigate the dose,efficacy and safety of pantoprazole in the prevention of duodenal ulcer.Methods The patients from October 2014 to October 2016,105 cases of neurosurgery,thoracic surgery,neurosurgery and orthopedic surgery were divided into group A,group B and group C according to random number table method,35 cases in each group.The three groups were treated with intravenous pantoprazole,the dosage of group A was 40mg,1 time/d;the dosage of group B was 80mg,1 time/d;the dosage of group C was 40mg,1 time/12h,treatment cycle was 1 week.Before and after treatment,the gastric pH change and onset time,the incidence of adverse reactions were compared among the three groups.Results After treatment for 24h,the gastric pH of group B was (5.15 ± 0.87),which was significantly higher than (2.35 ± 0.45) in group A and (3.59 ± 0.65) in group C,which in group C was significantly higher than that in group A(t =10.809,24.407,13.598,all P ＜ 0.05).The onset time of group B [(48.6 ± 12.2)] was significantly shorter than (88.7 ± 23.4) of group A and (85.4 ± 26.5) of group C (t =10.987,10.083,all P ＜ 0.05).In group B,the time of gastric pH ＞ 3 [(954.5 ± 156.4) rin],pH ＞ 4 time [(865.4 ±135.2)rin]and pH ＞5 time[(714.2 ± 115.4)min]were significantly longer than those in group A and group C,which in group C were significantly longer than that in group A,the differences were statistically significant (t =8.852,30.177,21,325,3.864,40.879,44.713,all P ＜ 0.05).The incidence rates of adverse reactions in group A,group B and group C were 5.71％,14.3％ and 8.6％,respectively,there was no statistically significant difference (t =4.175,45.149,43.974,all P ＜ O.05).Conclusion 80mg qd pantoprazole can significantly improve gastric pH,effectively prevent and treat duodenal ulcer,with high safety.