The invention provides an NNN tridentate ligand with a far-end hydroxyl group, and belongs to the technical field of metal organic chemistry. An auxiliary cantilever hydroxyl group is introduced to the far end of a coordination point nitrogen atom of the NNN tridentate ligand with the far-end hydroxyl group, and the hydroxyl group does not coordinate with a central metal due to spatial position limitation, and can interact with an exogenous molecule through a hydrogen bond or an electrostatic effect, so the regulation of the properties of the complex is achieved by the synergistic effect of the far-end groups. The synergistic mechanism is used to achieve efficient catalysis of a specific conversion process, so the ligand has an excellent catalytic activity in a hydrogen transfer reaction,and has a broad prospect in the development of high-efficiency catalysts.