Disclosed is an application of (3-((1H-pyrazol[3,4-b]pyridine-5-substituted)ethinyl)-4-methyl-N-(4-((4-methylpiperazine-1-substituted)methyl)-3-(trifluoromethyl)phenyl)benzamide) and pharmaceutically acceptable salts thereof in preparing drugs for treating acute lymphoblastic leukemia, and in particular, precursor B-cell lymphoblastic leukemia.