This study retrospectively analyzed the bronchoscopic manifestations in a pediatric case of diffuse pulmonary lymphangiomatosis (DPL), aiming to provide references for its early diagnosis. The child came to our hospital in August presented with “intermittent hemoptysis for 2 years and 8 months”, Despite previous left bronchial artery embolization, the hemoptysis persisted., and the qualitative test of ferritin was positive in several times of tracheoscopic lavage. After more than 2 years of oral corticosteroid therapy, the patient continued to experience recurrent hemoptysis.Ultimately, lung resection and pathological examination confirmed the diagnosis of DPL.This paper summarizes the bronchoscopic findings, noting that in the early stages, nodular protrusions visible under the bronchoscope exhibited an “appear-disappear” phenomenon, resembling a valve. Nine months later, a follow-up bronchoscopy revealed thin-walled vesicular manifestations under the bronchial mucosa at the same site, along with external compression of bronchial subsegments. These findings suggest that bronchoscopy can provide valuable insights for the early detection of DPL.