Background:This study aims to assess the efficacy and safety of ventilator for the treatment of atelectasis.Methods:We will search Cochrane Library, MEDLINE, EMBASE, CINAHL, EBSCO, Chinese database Chinese Biomedical Literature Database, China National Knowledge Infrastructure, and Wanfang data from inceptions to June 30, 2019 without language limitations. We will include randomized controlled trials (RCTs) of ventilator on evaluating the efficacy and safety of ventilator for atelectasis. We will use Cochrane risk of bias tool to assess the methodological quality for all included RCTs. RevMan 5.3 software will be used for statistical analysis.Results:The primary outcome is lung function. The secondary outcomes comprise of airway pressure, mean arterial pressure, arterial blood gas, heart rate, respiratory rate, oxygen saturation, and adverse events.Conclusion:The findings of this study will provide most recent evidence of ventilator for the treatment of atelectasis.Systematic review registration:PROSPERO CRD42019139329.