Abstract: OBJECTIVE To observe the effect of rapid on-site evaluation (ROSE) combined with next-generation sequencing (NGS) and dynamic monitoring of serum procalcitonin (PCT) on etiological diagnosis and treatment of pulmonary infections. METHODS A total of 90 patients with pulmonary infections who were treated in Maanshan Shiqiye Hospital from Jan. 2024 to Dec. 2025 were enrolled in the study and were randomly divided into the study group (ROSE plus NGS plus dynamic monitoring of PCT) and the control group (conventional etiological test plus experiential therapy), with 45 cases in each group. The therapeutic effect, treatment status, dynamic change of PCT, adverse event and withdrawal of antibiotics/dressing change were observed and compared between the two groups. RESULTS ROSE technology combined with NGS exhibited higher detection rates of bacterial, viral and mixed infections than the conventional tests did (P＜0.05). The total effective rate of the study group was 86.67%, higher than 68.89% of the control group(P＜0.05). The types of antibiotics, time of use of antibiotics, time of control of complications, length of hospital stay, cost of antibiotics, and the levels of PCT on Day 3, 7 and 10 of treatment were lower in the study group than in the control group(P＜0.05). The total incidence of adverse events of the study group was 33.33% in the control group, 13.33% in the study group; the incidence of drug withdrawal/dressing change was 22.22% in the control group, 6.66% in the study group, and there were significant differences (χ²=5.031,P=0.025;χ²=4.406,P=0.036). CONCLUSIONS ROSE technology combined with NGS can raise the detection rates of pathogens causing pulmonary infection, with notable advantages in identifying mixed infections, rare pathogens, and fastidious organisms. The combination with dynamic monitoring of PCT can intensify the therapeutic effect, facilitate the infection control, and reduce the unreasonable use of drugs and related risks so as to improve the prognosis of the patients.