This study aimed to develop a new disinfection device for the internal tubing of ventilators and evaluate its efficacy. The tandem device was designed to disinfect the internal tubing of ventilators with hydrogen peroxide (H₂O₂) dry mist that was produced by jet technique. Forty ventilators utilized for mechanical ventilation in confirmed infectious disease cases, each with ≥72 h of continuous operation, were included in the assessment. Colony-forming units (CFU) in air intake, air outlet, and internal tubing, were determined at the following time point, before disinfection, 1 h after disinfection, and 4 h after disinfection. The eligibility criteria were CFU≤20 per sample with no detectable pathogenic bacteria. All data were subjected to statistical analysis. The qualified rate was 0% before disinfection by H2O2, while it was 100% after disinfection for 1 h and 4 h, and CFU in each detection site was significantly lower after disinfection (p＜0.05), and no pathogenic bacterial growth was detected. The tandem H₂O₂ dry mist-disinfecting device is reliable and effective, and the expected effect could be achieved by 1 h disinfection.