The invention relates to a catalyst for preparing unsaturated aldehydes and unsaturated acids by an oxidation method and a preparation method thereof, and a synthesis method of the unsaturated aldehydes and the unsaturated acids, and is used for mainly solving the problem that the catalyst long
running activity is declined in the prior art. The problem is better solved by adopting the technical scheme that a carrier is at least one selected from SiO2 or Al2O3, and an
active component contains Mo12BiaFebXeYfZgQqOj, wherein X is at least one selected from Ni, Mg, Co, Ca, Be, Cu, Zn, Pb, Mn or Ba, Y is at least one selected from Zr, Nb, Sb or Ti, Z is at least one selected from K, Rb, Na, Li, Tl or Cs, and Q is at least one selected from La, Ce, Sm or Th. The catalyst can be used in industrial production of the unsaturated aldehydes and the unsaturated acids.