Objective: To discuss the clinical effect of bronchoalveolar lavage (BAL) combined with long term low dose azithromycin in the treatment of patients with bronchial dilation and its effect on lung function. Methods: A retrospective analysis of 83 cases with bronchiectasis treated in our hospital from February 2012 to December 2014, 44 patients were treated with conventional therapy combined with BAL and azithromycin (250 mg/times, twice a week, for 6 consecutive months) as the observation group, 39 patients in the control group only taking conventional therapy + BAL therapy, compared the clinical effect and lung function between the two groups. Results: Before treatment, at the end of the acute phase of the observation group and control group, the level of hs-CRP and WBC has no significant difference (P>0.05); after 6-month treatment, the level of serum hs-CRP in the observation group was significantly lower than the control group (P<0.05), and the sputum MD, MP score and sputum volume in the observation group was also significantly lower than those in the control group (P<0.05); at the end of the acute phase, the difference of PEF, FEV1, FVE1/pred measurement between the two groups was not statistically significant (P>0.05); after 6-month treatment, FEV1 and FVE1/pred in the observation group are significantly better than those in the control group (P<0.05). Conclusion: BAL combining long-term low-dose azithromycin has better clinical effect on the treatment of bronchiectasis, and also improves lung function better.