Objective: To explore the significance of M-mode uhrasoud direct measurement method, B ultrasound direct method and B ultrasound indirect method in the diagnosis of COPD patients. Methods: 40 patients with high risk COPD (high risk group and 40 low risk COPD patients (low risk group) were selected as the dividing line with the FEV1 account of the estimated value of%=50. The basic information of two groups of patients, lung function, blood gas, and the diaphragmatic muscles mobility of the three kinds of ultrasound and X - ray were recorded. Single factor and multiple factors analysis was used to screen indicators that affect the severity of chronic obstructive pulmonary disease (COPD). The correlation between the three ultrasonic measurements and X-ray measurement was analyzed. ROC analysis was used to evaluate the value of 3 kinds of ultrasonic measurement methods to predict the severity of COPD. Results: The mobility of M—mode uhrasoud direct measurement method, the degree of mobility of B ultrasonic direct method, the degree of mobility of B ultrasonic indirect method, and the degree of mobility under X - ray were the independent factors of high risk COPD patients. M hyper mobility, B ultrasound direct method mobility, B ultrasonic indirect hyper mobility and X ray mobility have significant positive correlation (r1=0.738, r2=0.667, r3=0.634, P<0.05). The M and X - ray combined diagnosis of COPD was the largest AUC in the diagnosis of 0.781. The minimum mobility of AUC was 0.610. The best diagnosis point of M super mobility is 16.795mm. Its sensitivity is 90% and specificity is 40%. The best diagnosis point is 24.32mm, and its sensitivity is 95% and specificity is 47%. Conclusion: M—mode uhrasoud direct measurement method, B-mode ultrasonography and B-mode ultrasound can be used for the diagnosis of chronic obstructive pulmonary disease. The effect of M ultrasound and X-ray combined diagnosis is better, and it is worthy of clinical promotion.