Objective To evaluate the effect of recruitment maneuvers by lung ultrasound before extubation under general anesthesia on patients undergoing ambulatory laparoscopic cholecystectomy. Methods A total of 80 patients, aged 18‒64 years, American Society of Anesthesiologists (ASA) grade Ⅰ or Ⅱ, who underwent ambulatory laparoscopic cholecystectomy were enrolled. According to the random number table method, they were divided into two groups (n=40): an observation group and a control group. All patients were under general anesthesia. Before extubation, the lungs were resuscitated using the tidal volume increment method in the observation group, the control group was not resuscitated. Lung ultrasound score (LUS) were recorded for patients in the two groups 1 h before surgery (T1), 30 min after removal of tracheal catheter (T2), and 20‒30 h after surgery (T3). The LUS of each division and the pulmonary oxygen concentration (SpO2) were recorded at each time point. Meanwhile, their sex ratio, age, body weight, body mass index (BMI), ASA grade, mechanical ventilation time, operation time, and the Numerical Rating Scale (NRS) scores at T2 and T3 were recorded. Results There was no significant difference in sex ratio, age, body weight, BMI, ASA grade, mechanical ventilation time, operation time, and NRS scores at T2 and T3 between the two groups (P>0.05). Compared with those at T1, the LUS at T2 and T3 increased in the two groups (P<0.05). Compared with those at T2, the LUS at T3 decreases in the two groups (P<0.05). Compared with the control group, the LUS of the observation group decreased at T2 and T3 (P<0.05), and SpO2 increased at T3 (P<0.05). Compared with those in the ipsilateral superior anterior area, the LUS of both upper and lower posterior areas significantly increased in the two groups at T2 and T3 (P<0.05). In the control group, the LUS increased in the left upper area, left lower area and right lower area at T2 and in the right lower anterior area at T3 (P<0.05). The LUS of the left upper area, left lower area, left upper posterior area, left lower posterior area, right lower area, right upper posterior area and right lower posterior area in the observation group were significantly lower than those in the control group at T2 (P<0.05). The LUS of the right upper area and right upper posterior area in the observation group were lower than those in the control group at T3 (P<0.05). Conclusions After ambulatory laparoscopic cholecystectomy, lung air content may decrease to some extent, which persists until at least one day after surgery; recruitment maneuvers with increasing tidal volume before tracheal tube removal can improve the symptom to some extent and maintain good oxygenation after operation. Lung ultrasonography provides good assessment of reduced lung air content.