〔Abstract〕 Objective To investigate the effect of fiberoptic bronchoscopy alveolar lavage in patients with severe ventilatorassociated pneumonia (VAP) and its influence on respiratory dynamics. Methods A total of 103 patients with severe VAP admitted to Jiamusi Central Hospital from July 2019 to June 2020 were selected as the research objects. The patients were divided into group A (51 cases, conventional treatment) and group B (52 cases, bronchoscopic alveolar irrigation) by randomized grouping method. Clinical efficacy, clinical pulmonary infection score (CPIS) and respiratory dynamics were compared between the two groups. Results The total effective rate of clinical treatment in group B was significantly higher than that in group A, with statistical significance (P < 0.05). On day 7 after treatment, CPIS in group B was lower than that in group A, the difference was statistically significant (P < 0.05). 4 h after treatment, the resistance in airway (Raw) and airway peak inspiratory pressure (PIP) in group B were lower than those in group A, and the dynamic compliance (Cdyn) was higher than that in group A, with statistical significance (P < 0.05). Conclusion The application of fiberbronchoscope in patients with severe VAP has significant clinical effect, which can effectively control pulmonary infection and significantly improve the respiratory dynamics index of patients.