Objective To analyze the efficacy and safety of nalbuphine in patients with sedative analgesia in intensive care unit (ICU). Methods A prospective observation was conducted. The adult patients with mild and moderate analgesia in general ICU of the First Affiliated Hospital of Zhengzhou University from January to November in 2017 were enrolled, and they were divided into nalbuphine group and sufentanil group in proper order. The nabobrown group was given 40 mg nabobrown, the sufentanil group was given 0.1 mg sufentanil, both of which were injected with 50 mL normal saline for continuous intravenous infusion in micro-pump. Infusion speed was checked according to pain level. The analgesic target was critical-care pain observation tool (CPOT) score < 2. The change in hemodynamics of patients in both groups were observed, and CPOT score and Richmond agitation-sedation scale (RASS) score were recorded before and l, 3, 5, 12, 24 hours after administration. The analgesic and sedative effects of two drugs were evaluated. Results A total of 141 patients were enrolled, including 71 patients in nalbuphine group and 70 in sufentanil group. There was no significant difference in general data including gender, age, body weight, acute physiology and chronic health evaluation Ⅱ (APACHEⅡ) or pain source, as well as baseline hemodynamics parameter between the two groups. At 1 hour and 3 hours after administration, nalbuphine had no effect on blood pressure, but the heart rate was decreased slightly, while the heart rate and blood pressure of the sufentanil group were decreased obviously. The two drugs could make the heart rate and blood pressure fluctuate obviously with the time of medication, but there was no statistical difference between the two drugs. The two drugs had no significant effect on pulse oxygen saturation (SpO2) during analgesia. The average dosage of nalbuphine was 0.03 (0.02, 0.05) mg·kg-1·h-1in the nalbuphine group, and the patient was satisfied with the analgesic effect until 3 hours after the use of the drug, and CPOT score was significantly decreased as compared with that before administration [1.0 (1.0, 2.0) vs. 3.0 (2.0, 4.0), P < 0.01], and the sedative effect was increased, RASS score was significantly lower than that before administration [0 (0, 1.0) vs. 1.0 (1.0, 2.0), P < 0.01]. No patients in naporphine group were treated with sufentanil due to unsatisfactory analgesia. The average dosage was 0.11 (0.06, 0.14) μg·kg-1·h-1in the sufentanil group, the patient was satisfied with the analgesic effect until 5 hours after administration, and the CPOT score was significantly lower than that before administration [1.0 (1.0, 2.0) vs. 4.0 (3.0, 6.0), P < 0.01], and the sedative effect was significantly increased, RASS score was significantly lower than that before administration [0 (-1.0, 0) vs. 2.0 (1.0, 2.0), P < 0.01]. The scores of CPOT and RASS in the sufentanil group were significantly higher than those of the naporphine group before use, so the decrease in the CPOT and RASS scores of the two drugs was further analyzed, which indicated the decrease in CPOT score of naporphine group was significantly lower than that in sufentanil group from 3 hours on [1.0 (0, 2.0) vs. 2.0 (1.0, 3.0), P < 0.05], and the decrease in RASS score of naporphine group was significantly lower than that in sufentanil group from 1 hour on [0 (0, 1.0) vs. 1.0 (0, 2.0), P < 0.01]. It suggested that naporphine could achieve sustained and stable analgesic effect and avoid excessive sedation caused by sufentanil. Conclusions Naporphine had a sustained and stable analgesic effect on patients with mild and moderate ICU analgesia. The onset time of naporphine was equivalent to sufentanil, and it had a certain sedative effect and less influence on hemodynamics.