Objective To explore the effect of different ventilation modes during laparoscopic radical resection of colorectal cancer (LRRCC) on respiratory function in patients with complicated mild obstructive ventilatory disorder (OVD).Methods 68 patients with mild OVD who underwent elective LRRCC from June 2022 to March 2024 were randomly divided into a volume controlled ventilation (VCV) group (n = 34, with intraoperative VCV) and a pressure controlled ventilation-volume guaranteed (PCV-VG) mode group (n = 34, with intraoperative PCV-VG). Changes in hemodynamics [mean arterial pressure (MAP) and heart rate (HR)], blood gas indicators [partial pressure of carbon dioxide in arterial blood (PaCO₂) and arterial partial pressure of oxygen (PaO₂)], lung exchange function indicators [oxygenation index (OI), alveolar-arterial oxygen partial pressure difference (P_A-aO₂)], respiratory mechanics indicators [tidal volume, end-tidal carbon dioxide partial pressure (PetCO₂), peak airway pressure (Ppeak), and dynamic lung compliance (C_ldyn)] before pneumoperitoneum (T₁), 30 min after establishing pneumoperitoneum (T₂), 1 h after pneumoperitoneum (T₃), and 20 min after the end of pneumoperitoneum (T₄) were observed in both groups. And incidence of intraoperative complications and the positive rate of postoperative pulmonary complication (PPC) in both groups were counted.Results There were no statistically significant differences in MAP and HR between the two groups at T₁, T₂, T₃ and T₄ time points (P > 0.05). The PaCO₂ level in both groups at T₂, T₃, and T₄ time points was higher than that at T₁ time point, but the PCV-VG group was lower than that in the VCV group, the differences were statistically significant (P < 0.05). The PaO₂, OI, and C_ldyn in the two groups at T₂ and T₃ time points were lower than those at T₁ time point, but the PCV-VG group was higher than that in the VCV group, the differences were statistically significant (P < 0.05). The P_A-aO₂, tidal volume, PetCO₂ and Ppeak of the two groups of patients at T₂ and T₃ time points were significantly higher than those at time point T₁, and the differences were statistically significant (P < 0.05). At T₂ and T₃, the P_A-aO₂ and Ppeak in the PCV-VG group were significantly lower than those in the VCV group, and the differences were statistically significant (P < 0.05). The incidence of intraoperative complications and PPC positivity rate in the PCV-VG group were 8.82% and 2.94%, respectively, which were lower than 29.41% and 23.53% in the VCV group, the differences were statistically significant (P < 0.05).Conclusion Compared with VCV, implementing PCV-VG mode during LRRCC surgery is more conducive to reducing the impacts of pneumoperitoneum on blood gas analysis, lung ventilation function, and respiratory mechanics, and reducing the incidence of complications such as hypoxemia and hypercapnia rate. It is worthy for clinical application.