We conducted a prospective randomized controlled trial to evaluate the effect of evidence-based nursing care on length of hospital stay, duration of mechanical ventilation, symptom relief, and complication rates among mechanically ventilated children with severe adenovirus pneumonia. A total of 257 children admitted to Hunan Provincial People's Hospital in Changsha from February 2018 to December 2021 were enrolled. Two patients withdrew from the study, resulting in 124 cases in the conventional care group and 131 cases in the evidence-based care group. Primary outcomes included time to resolution of signs and symptoms, length of hospital stay, complication rates. Secondary outcomes were blood biomarker levels and successful weaning results. The evidence-based care group demonstrated significantly higher overall efficiency than the conventional care group (98.47% vs. 95.97%, p<
0.05). Additionally, the evidence-based care group demonstrated quicker resolution of cough, sputum, pulmonary rales, and fever, shorter hospital stays, and reduced need for mechanical ventilation (p <
0.05). The evidence-based care group had a significantly lower complication rate than the conventional care group (9.16% vs. 25.00%, p <
0.05). Post-care blood biomarker analysis showed decreased levels of leukocytes, calcitonin, and C-reactive protein in the evidence-based care group compared to the conventional care group (p<
0.05). Evidence-based nursing interventions can improve outcomes for children with adenovirus pneumonia by reducing comorbidities, improving blood gas levels, reducing inflammatory responses, and improving the weaning success rate of mechanically ventilated children with severe adenoviral pneumonia.