Objective：To explore the application and value of lung ultrasound score in patients with coronavirus disease 2019 （COVID-19） complicated with acute respiratory distress syndrome（ARDS）. Methods：A total of 18 patients with COVID-19 compli－cated with ARDS in a Wuhan hospital were selected. The prospective double-blind cohort study was performed and patients’ clinical data were recorded. Chest computed tomography（CT） and lung ultrasound were performed and CT was regarded as the “golden stan－dard” to evaluate the value of ultrasound in diagnose lung atelectasis/consolidation. Pearson correlation test was used to compare the correlation between lung ultrasound score and oxygenation index and COVID-19 complicated with ARDS. ROC curve was used to evaluate the threshold of lung ultrasound score to predict sensitivity and specificity of COVID-19 complicated with severe ARDS. Results：Among these 18 patients，a total of 38 times chest CT and lung ultrasound were performed and 456 lung regions were exam－ined，among which 185 were lung atelectasis/consolidation via CT，while 166 were atelectasis/consolidation via ultrasound. Sensitivity，specificity，positive predictive value，negative predictive value and diagnostic accuracy of lung ultrasound were 83.9%，95.9%，93.4%，89.7% and 91.0% respectively. The correlation coefficient between lung ultrasound score and oxygenation index was significantly cor－related（r=-0.812）. Taking lung ultrasound score of 20.5 as the threshold value，the area under ROC curve for COVID-19 complicated with ARDS was 0.885，the sensitivity was 76.9% and the specificity was 88.0%. Conclusion：Lung ultrasound is simple to perform and has a relatively high efficiency to COVID-19 complicated with ARDS. Lung ultrasound score can be used in assessing the severity of COVID-19 complicated with ARDS and is worthy of promotion.