The invention belongs to the technical field of catalyst preparation, and in particular relates to a chiral catalyst, (S)-DTP-COF and its preparation method and application. Wherein, the preparation method of the chiral catalyst (S)-DTP-COF is: trifluoromethanesulfonate cuprous, (S,S)-2,6-bis(4-phenyl-2-oxazoline-2 - Base) pyridine is placed in a round-bottomed flask, with chloroform as a solvent, stirring and dissolving. Add 2,5-dimethoxybenzene-1,4-diformaldehyde, 1,3,5-tris(4-aminophenyl)benzene and phenylacetylene into a round bottom flask, and stir at room temperature for 48 hours. Finally, add acetic acid and stir for 24‑48h to obtain (S)‑DTP‑COF. The catalyst can effectively catalyze the Michael addition reaction, and can realize heterogeneous catalysis without high temperature, less catalyst consumption and no other additives. At the same time, the catalyst can be reused and recycled easily, which improves the utilization rate of the catalyst, reduces the cost, and is beneficial to industrial popularization and application.