Objective To explore the application effect of midazolam combined with sufentanil citrate in analgesia and sedation in patients with sepsis-related Acute respiratory distress syndrome (ARDS) undergoing mechanical ventilation. Methods: 96 patients with sepsis-related ARDS who received mechanical ventilation and were admitted to our hospital from March 2022 to March 2024 were selected as the research subjects. The patients were divided into the control group and the observation group by random number table method, with 48 cases in each group. The control group was sedated with midazolam. The observation group was treated with midazolam combined with sufentanil citrate for sedation. The vital sign indicators [Heartrate (HR), Mean arterial pressure (MAP)], sedative effect (Ramasy sedation score), serum inflammation [Tumor necrosis factor alpha (TNF-α), Interleukin-6 (IL-6)], stress responses [Cortisol (Cor), Adrenocorticotropic hormone (ACTH)], and the incidence of adverse reactions of the two groups were collected and compared. Results: The fluctuation amplitudes of HR and MAP at 2 h and 6 h after medication in the observation group were significantly smaller than those in the control group (P < 0.05). The Ramasy sedation scores of the observation group at 2 h and 6 h after medication were significantly higher than those of the control group (P < 0.05). The levels of TNF-α, IL-6, Cor and ACTH in the observation group 1 day after administration were significantly lower than those in the control group (P < 0.05). There was no significant difference in the total incidence of adverse reactions between the two groups (P > 0.05). Conclusion: Midazolam combined with sufentanil citrate in the sedation of patients with sepsus-related ARDS undergoing mechanical ventilation can improve the analgesic effect, stabilize the vital signs of patients, reduce the stress response and inflammatory response, and has a relatively high safety.