The invention relates to a foam-like low-temperature SCR catalyst and a preparation method thereof. The catalyst is composed of a framework carrier and an active coating carried by the framework carrier. Foam ceramic of a 3D porous structure serves as the framework carrier. The active coating is composed of active components, auxiliaries and base materials. The inner portion of the foam-like low-temperature SCR catalyst is of a staggered 3D porous structure, smoke moves in ducts in a curve mode, the mixing effect of smoke and reducing agents is optimized, the utilization rate of reducing agents is increased, and ammonia escape is reduced. The catalyst has excellent low-temperature activity for NOx reduction, the removal efficiency for NOx under the condition that the smoke temperature is 170-180 DEG C is kept at 90% or above, and the catalyst has high thermal stability and sulfur-resistant capacity.