〔Abstract〕 Objective To investigate the molecular mechanisms related to angiogenesis during the development and progression of diabetic retinopathy (DR). Methods Angiogenesis-related genes were obtained from the Gencard website and intersected with differentially expressed genes from DR datasets (GSE60436 and GSE94019). Functional enrichment and protein-protein interaction (PPI) networks were then used to screen candidate genes and evaluate their diagnostic value. Gene set enrichment analysis (GSEA) was used to explore potential pathways underlying candidate genes, and immune infiltration analysis revealed associations between candidate genes and immune cells. Cellular experiments were conducted to validate the role of fibronectin 1 (FN1) in human retinal microvascular endothelial cells (HRMECs) under high glucose (HG) conditions. Results A total of 237 differentially expressed genes related to angiogenesis were identified, enriched in pathways such as phosphoinositide 3-kinase/protein kinase B signaling pathway (PI3K-Akt), tumor suppressor protein 53 (P53), tumor necrosis factor (TNF), and Janus kinase (JAK)/signal transducer and activator of transcription signaling pathway (STAT). Among them, collagen type I alpha 1 chain (COL1A1), COL1A2, FN1, tumor necrosis factor (TNF), and tumor protein p53 (TP53) were key genes with high diagnostic value. GSEA indicated that these genes were involved in multiple signaling pathways, including P53. CIBERSORTx analysis revealed significant associations with the infiltration of multiple immune cells. HG treatment led to the upregulation of FN1. In HG-induced HRMECs, compared with the si-NC control group, si-FN1 significantly reduced cell proliferation, migration, and tube formation, while P53 protein expression was increased. Conclusion This study reveals the important role of FN1 in angiogenesis in DR and suggests that it may be a potential diagnostic and therapeutic target.