Objective To compare the effectiveness and safety of different self‑control doses of sufentanil for postoperative patients control intravenous analgesia (PCIA) in patients aged 1‒7 years. Methods Children who were scheduled for surgery under general anesthesia received PCIA, with a total amount of sufentanil of 2 μg/kg which was diluted with 0.9% sodium chloride to 100 ml, a background dose of 2 ml/h (0.04 μg·kg−1·h−1 sufentanil), and a locking interval of 15 min. According to the random number table method, the patients were divided into two groups: group PCIA1 (where the single self‑control dose of sufentanil was 0.02 μg/kg) and group PCIA2 (where the single self‑control dose of sufentanil was 0.01 μg/kg). Their Face, Legs, Activity, Cry, Consolability (FLACC) analgesia scores, Ramsay sedation scores, the actual number of compression, the number of effective compression, and rescue doses were recorded 0.5 h (T0.5), 1 h (T1), 2 h (T2), 6 h (T6), 12 h (T12), 24 h (T24) and 48 h (T48) after surgery. The adverse reactions, including nausea, vomiting, itchy skin, hypersedation and respiratory depression were recorded. Results At T0.5, T1, and T2, group PCIA1 presented lower FLACC, higher Ramsay scores, and a higher proportion of moderate sedation than group PCIA2 (P<0.05). Group PCIA1 presented increases in the total rate of effective compression and total rescue dose, decreases in the rate of effective compression at T0.5 and the actual number of compression at T1 and T2, and increases in rescue dose T12 and T24, compared with group PCIA2 (P<0.05). No statistical difference was found in adverse reactions between the two groups (P>0.05). Conclusions For patients aged 1‒7 years who are scheduled for surgery and receive PCIA with sufentanil at 0.04 μg·kg−1·h−1, a single controlled dose of 0.02 μg/kg is superior to 0.01 μg/kg, which produces better analgesic and sedative effects without changes in the incidence of adverse reactions.