Objective To compare the efficacy and safety of cap-assisted endoscopic sclerotherapy (CAES) and procedure for prolapse and hemorrhoids (PPH) for internal hemorrhoids. Methods This study was a prospective double-blind controlled clinical one. A total of 80 patients with internal hemorrhoids who visited Baoding No.1 Central Hospital from March 2018 to March 2020 and met the inclusion and did not meet exclusion criteria, were randomly divided into CAES group (n=40) and PPH group (n=40) by random number table method, and received corresponding treatment respectively. The perioperative indices of the two groups were compared, including intraoperative blood loss, operation time, visual analogue scale (VAS) score at 24 and 48 hours after operation, length of hospital stay, treatment costs, time to return to normal life, and curative rates. The complications within 3 months after operation and the 1-year recurrence after operation were also compared between the two groups. Results The operation was successfully completed in all patients. The intraoperative blood loss (0.54±0.15 mL VS 7.32±2.17 mL) and treatment cost (6 249.53±435.67 yuan VS 7 832.96±526.74 yuan) in CAES group were significantly lower than those in PPH group (t=19.714, P<0.05; t=14.650, P<0.05). The length of hospital stay (3.53±0.94 d VS 5.18±1.36 d) and time to return to normal life (5.26±1.28 d VS 7.17±2.09 d) in CAES group were significantly lower than those in PPH group (t=6.312, P<0.05; t=4.929, P<0.05). There was no significant difference in operation time between the two groups (t=0.977, P>0.05). The VAS scores at 24 h (2.64±0.70 points VS 3.59±0.93 points) and 48 h (1.28±0.31 points VS 2.16±0.57 points) after operation in CAES group were significantly lower than those in PPH group (t=5.162, P<0.05; t=8.578, P<0.05). There was no significant difference in the curative rate [90.0% (36/40) VS 97.5% (39/40)] between CAES group and PPH group (χ2=0.853, P=0.356). During the follow-up period within 3 months after the operation, the incidence of urinary retention [0.0% (0/40) VS 15.0% (6/40)] and pain [2.5% (1/40) VS 22.5% (9/40)] in CAES group was significantly lower than those in PPH group (χ2=4.504, P<0.05; χ2=7.314, P<0.05). No other complications occurred in the 80 patients. After 1 year of follow-up, the recurrence rate of CAES group was 7.5% (3/40), which was not statistically different from that in PPH group [5.0% (2/40), χ2=0.180, P>0.05]. Conclusion As a new minimally invasive technique for the treatment of internal hemorrhoids, CAES has similar curative rate and 1-year recurrence rate to PPH. Compared with PPH, CAES shows the advantages of less trauma, less pain, faster recovery and lower cost.