The present invention provides a cracking catalyst, containing a rare-earth Y-zeolite and a support, which is characterized in that the rare-earth content in crystal lattice of the rare-earth Y-zeolite is 4-15 wt % of RE2O3; the original unit cell size is 2.440-2.465 nm; the equilibrium unit cell size of the catalyst after 100% steam-aging treatment at 800° C. for 17 hours is larger than 2.435 nm; the rare-earth atom content in the support is 1.0-8.0 wt % of the support. The present invention also relates to a preparation process for the same catalyst.