Objective To observe the effect of ultrasound-guided lung recruitment strategy on vital signs and incidence of postoperative adverse reactions in patients undergoing laparoscopic sleeve gastrectomy. Methods Using a random number table,a total of 80 patients who underwent laparoscopic sleeve gastrectomy from March 2020 to March 2024 were selected and divided into two groups, with 40 patients in each group. Both groups received combined intravenous and inhalational anesthesia during surgery. On this basis, the control group received traditional lung recruitment maneuver during anesthesia recovery, while the observation group received ultrasound-guided lung recruitment strategy. Comparisons were conducted for the blood oxygen saturation （SpO₂）, mean arterial pressure （MAP）, heart rate （HR）, and arterial oxygen partial pressure/fraction of inspiratory oxygen （PaO₂/FiO₂） of the two groups at 5 min before anesthesia induction （T0）, before lung recruitment at the end of surgery （T1）, after lung recruitment （T2）, 30 min after extubation （T3）, and 1 d after surgery （T4）. The incidences of postoperative adverse reactions （atelectasis, pneumonia, pleural effusion, hypoxemia） were analyzed in the two groups. Results The incidence rates of postoperative adverse reactions were lower in the observation group than in the control group （P<0.05）. At T0 and T1, the SpO₂ levels between the two groups were not different （P>0.05）. At T2, T3, and T4, the SpO₂ levels in the observation group were higher than those in the control group （P<0.05）. At T1 and T2, both groups showed a decrease in MAP and HR compared to T0 （P<0.05）. At T2 and T3, there was no significant difference in MAP and HR between the observation group and the control group （P>0.05）. At T2, T3, and T4, the PaO₂/FiO₂ levels in the observation group were higher than those in the control group （P<0.05）. Conclusion The ultrasound-guided lung recruitment strategy for patients undergoing laparoscopic sleeve gastrectomy does not affect the stability of vital signs, and can improve oxygenation and reduce postoperative adverse reactions.