Objective To investigate the influencing factors for the progression of glomerular injury in children with Henoch-Schönlein purpura nephritis (HSPN) and to develop a predictive model. Methods A total of 259 children with HSPN admitted to the First Affiliated Hospital of Henan University of Traditional Chinese Medicine from January 2022 to December 2024 were retrospectively enrolled. Based on renal biopsy pathology reports, the children were classified into a low-grade group (grade Ⅰ-Ⅱ glomerular injury; n=61), and a high-grade group (grade Ⅲ-Ⅵ glomerular injury; n=198). Clinical indicators and pathological characteristics were compared between the two groups. A multivariable logistic regression model was constructed to predict progression to high-grade injury. The model's discrimination and calibration were evaluated using receiver operating characteristic curve analysis and the Hosmer-Lemeshow goodness-of-fit test. Results Compared with the low-grade group, the high-grade group showed significantly higher urinary red blood cell count, urinary cast count, urinary small round epithelial cell count, urine protein-to-creatinine ratio, urinary IgG-to-creatinine ratio, urinary N-acetyl-β-D-glucosaminidase, fibrinogen, white blood cell count, and neutrophil-to-lymphocyte ratio, while albumin, albumin-to-globulin ratio, and prothrombin time were significantly decreased (all P<0.05). The proportions of patients with dyslipidemia, diffuse mesangial hyperplasia, glomerular segmental sclerosis or adhesion, tubular atrophy/interstitial fibrosis, and crescent formation were also significantly higher (all P<0.05). Multivariable logistic regression identified urinary small round epithelial cell count, urine protein-to-creatinine ratio, fibrinogen level, albumin level, neutrophil-to-lymphocyte ratio, and dyslipidemia as factors associated with progression from low to high-grade injury (all P<0.05). A prediction model was constructed based on these variables. The Hosmer-Lemeshow test indicated excellent calibration (P=0.977). Receiver operating characteristic analysis showed an area under the curve of 0.818 (95%CI: 0.766-0.863), with a sensitivity of 71.2% and a specificity of 80.3% (P<0.05). Conclusions Children with higher-grade glomerular injury from HSPN exhibit more severe clinical and pathological manifestations. The prediction model incorporating urinary small round epithelial cell count, urine protein-to-creatinine ratio, fibrinogen level, albumin level, neutrophil-to-lymphocyte ratio, and dyslipidemia demonstrates good predictive performance for identifying progression to high-grade (Ⅲ-Ⅵ) glomerular injury and has potential for clinical application.