The invention provides a catalyst for preparing propylene from butylene and a preparation method thereof. The preparation method comprises the following steps: mixing a CHA/AEI eutectic molecular sieve, a carrier raw material and sesbania cannabina powder, so that mixed powder is obtained; adding an inorganic acid solution into the mixed powder, and mixing; and mixing, kneading, carrying out extrusion moulding, drying at the temperature of 90-120 DEG C, and roasting for 2 hours at the temperature of 500-600 DEG C, so that the catalyst for preparing propylene from butylene is obtained. The catalyst for preparing propylene from butylenes, prepared by adopting the preparation method, can catalyze reaction for preparing propylene from butylene, and the propylene selectivity and yield are high.