The invention relates to the field of petrochemical engineering, in particular to an alkaline treating method of an aluminium isopropoxide waste catalyst and a treating device thereof. According to the method, strong alkaline solutions of sodium hydrate (or potassium hydrate) and the like are taken as alkaline hydrolysis extractants, alkaline hydrolysis extracting is conducted on the input isopropanol aluminum waste catalyst, and separation is conducted on an organic phase and an inorganic phase; useful parts of the separated organic phase are further recovered; pseudo-boehmite with high addedvalue is obtained after the PH value of the separated inorganic phase is adjusted through CO2, and carbonate crystals can be recovered by filtering liquid through a manner of condensed crystallization. By means of the method, the treating problem of wasted catalysts in the reduction production process of unsaturated aldehydes and ketones is solved, certain benefits can be achieved, and the greendegree of the reduction production process of the unsaturated aldehydes and ketones taking the aluminium isopropoxide as a catalyst is improved.