Considering the essential role of FLT3-ITD mutations in the development of acute myeloid leukemia (AML), the research and development of FLT3 inhibitors hold significant therapeutic potential. In this study, we identified a novel, highly potent small molecule inhibitor, FLIN-4, targeting FLT3 through structure-based virtual screening. Notably, FLIN-4 showed exceptional inhibitory effects in kinase activity inhibition assays, exhibiting a potent inhibitory effect against FLT3 (IC