Objective To observe the effects of mechanical deep expectoration on expectoration effect, respiratory mechanics and levels of inflammatory factors in patients with pulmonary infection. Methods: A total of 98 patients with pulmonary infection in our department during the period from February 2023 to February 2025.were selected as the research subjects. They were grouped by the coin-tossing method. In the control group, 49 cases were given traditional manual tapping for expectoration, and in the observation group, 49 cases were given mechanical deep expectoration. Compare the expectoration effect, respiratory mechanics [Peak Inspiratory Pressure (PIP), Airway Resistance (RAW), and Dynamic Lung Compliance] of patients with pulmonary infection in the two groups. Cdyn), Work of Breathing (WOB), levels of inflammatory factors [Interleukin-6 (IL-6), C-reactive protein CRP and Procalcitonin (PCT) and quality of life [Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36)]. Results: The total effective rate of the observation group was 91.83% (45/49), which was higher than that of the control group at 75.51% (37/49) (P < 0.05). Before the intervention, the comparison of respiratory mechanics between the two groups of patients with pulmonary infection (P > 0.05); After the intervention, the PIP, RAW and WOB of patients with pulmonary infection in both groups decreased, and those in the observation group were lower (P < 0.05). The Cdyn increased, and it was higher in the observation group (P < 0.05). Before the intervention, the levels of inflammatory factors in the two groups of patients with pulmonary infection were compared (P > 0.05); After the intervention, the levels of IL-6, CRP and PCT in both groups of patients with pulmonary infection decreased, and those in the observation group were lower (P < 0.05). Before the intervention, the comparison of the quality of life of patients with pulmonary infection in the two groups (P > 0.05); After the intervention, the scores of each sub-item of SF-36 in both groups of patients with pulmonary infection decreased, and the score in the observation group was lower (P < 0.05). Conclusion: Compared with the traditional manual tapping method for expectoration, the application of mechanical deep expectoration in patients with pulmonary infection can effectively improve the expectoration effect, improve the levels of respiratory mechanics and inflammatory factors, and enhance the quality of life.