The invention provides a catalyst dephosphorizing yellow phosphorus tail gases and a preparation method thereof. The method comprises: dipping a surface treated active carbon carrier into a metal salt solution; and dropping a pyrophosphate or phosphatic solution into the solution after dipping to adjust a pH value to make the solution be alkaline, wherein the metal salt solution and the pyrophosphate or phosphatic solution react to generate a metal phosphate or a pyrophosphate deposition which does not react with a sulfide, the deposition is adhered on the carrier, and the catalyst for dephosphorizing the yellow phosphorus tail gases is obtained after aging, filtrating and drying processes. The catalyst of the invention has strong endurance against sulfides, can make the yellow phosphorus tail gas dephosphorization purification reaction be continuously carried out under a certain reaction condition, and has no need to generation.