Objective To investigate the clinical effect of bronchoalveolar lavage with ambroxol injection by branchofiberoscope in the treatment of lobar pneumonia. Methods From Dec. 2014 to Dec. 2016, a total of 200 children with lobar pneumonia in Women and Children Health Care Center of Luoyang were randomly divided into observation group (n=100) and control group (n=100). Both groups were given routine drug for relieving cough, reducing sputum and inflammation, besides, the observation group was given additional bronchoalveolar lavage with ambroxol injection by branchofiberoscope. The improvement time of clinical symptoms (defervescence time, cough anesis time, pulmonary rales disappearance time), hospital stay, and adverse reactions in the two groups were compared. Results The total effective rate in the observation group was 96% which was significantly higher than that in the control group 81%, their difference was statistically significant (P<0.05). The defervescence time, cough anesis time, pulmonary rales disappearance time and hospital stay in the observation group were all significantly shorter than those in the control group, their differences were statistical significant (P<0.05). The adverse reaction rate in the observation group was 6% which was lower than that in the control group 12%, but there was no significant difference between the two groups (P>0.05). Conclusion Bronchoalveolar lavage with ambroxol injection by branchofiberoscope which has high clinical value in the treatment of lobar pneumonia, is helpful to improve the clinical symptoms and accelerate the prognosis of children.