Objective To approach influence of pulmonary function for brain damage children by external diaphragm pacemaker with respiratory rehabilitation nursing technique in convalescence period.Methods A total of 60 cases brain damage children treated in Shenyang Children′s Hospital from July 2019 to July 2020 were selected as objects of study,who were divided into the control group (30 cases) and the detection group (30 cases) by random slip method.The control group used routine inhalation rehabilitation nursing health instruction,the detection group used external diaphragm pacemaker with respiratory rehabilitation nursing technique,the pulmonary function index,suction index,daily life quality score of two group before intervention and after intervention were compared.Results The lung capacity,maximum ventilation percentage,oxygenation,oxygenation index,peak airway pressure,airway resistance,daily life quality score of two group before intervention were compared,the differences had no statistical significance (P＞0.05).After intervention,lung capacity,maximum ventilation percentage,oxygenation,oxygenation index,airway resistance,daily life quality score of the two groups were higher than those before intervention,peak airway pressure was lower than that before intervention;lung capacity,maximum ventilation percentage,oxygenation,oxygenation index,airway resistance,daily life quality score of detection group were higher than those of the control group,peak airway pressure was lower than that in the control group,the differences had statistical significance (P＜0.05).Conclusion The application of pulmonary function for brain damage children by external diaphragm pacemaker with respiratory rehabilitation nursing technique in convalescence period,which could improve pulmonary function and suction index of children,increase daily life quality of children,it is worth to be used.