The invention relates to the technical field of engine manufacturing, in particular to a dry cylinder liner cylinder block body core and an assembling method thereof. The dry cylinder liner cylinder block body core comprises a front end core body, a rear end core body, a big cylinder core body, a water jacket core body, a tappet core body and a pillow core body, wherein the number of through holes formed in either the water jacket core body or the pillow core body is the same as that of through holes in the big cylinder core body; slide blocks are arranged at the two ends of the water jacket core body; slide grooves matched with the slide blocks are formed in the sides, near the big cylinder core body, of the front end core body and the rear end core body correspondingly; joggle joint is adopted at the two ends, corresponding to the tops of the front end core body and the rear end core body, of the pillow core body; plug grooves are formed in the big cylinder core body and used for the plugging of the tappet core body in a connected mode; and the tappet core body is vertically plugged between the big cylinder core body and the pillow core body in the connected mode. Special moulds are not required for the body core assembling, and the operation is simple.