The invention discloses a preparation method of a cracking catalyst containing ultrastable molecular sieve, comprising the followings steps: (1) mixing certain amount of a host material, hydrochloric acid and deionized water according to formula requirements for pulping, adding NaY molecular sieve and mixing evenly, then feeding obtained material to a spray drying system to dry for shaping, thus obtaining catalyst powder; and (2) mixing the catalyst powder with a salt solution to be exchanged and stirring evenly, exchanging for at least 1h, cooling, washing and drying, roasting at the temperature of 500-700 DEG C with 100% of water vapor to obtain the cracking catalyst utilizing ultrastable Y type molecular sieve as active component. By adopting the method provided by the invention, the size of original grain in catalyst can be effectively kept, thus improving the dispersibility and crystallinity of the molecular sieve, effectively reducing runoff material, lowering salt usage during the modification process of the molecular sieve, lowering production cost and protecting environment.