The invention discloses marbled glass ceramics directly employing fusion blast furnace slag and a preparation method of the marbled glass ceramics. The marbled glass ceramics comprises the following raw materials, by mass, 55-75 parts of blast furnace slag flux and 25-45 parts of auxiliary material flux; and auxiliary materials comprise the following components, by mass, 8.5-19.5 parts of quartz sand, 0.5-5.5 parts of limestone, 1-5 parts of sodium carbonate, 2-5 parts of potassium carbonate, 1-4 parts of zinc oxide, 1-4 parts of ammonium di-hydrogen phosphate, 1-2 parts of spodumene, 2.5-5 parts of sodium fluosilicate, 0.5-1.5 parts of sodium fluoroaluminate and 0.5-1 part of borax. The preparation method is characterized in that through controlling the mixed melting temperature and time of the blast furnace slag flux and the auxiliary material flux, a flux mixture is obtained; through forming, annealing and microcrystallization heat treatment, the marbled glass ceramics is obtained. The molten blast furnace slag and the auxiliary materials are mixed in a flux form and the flux mixture having certain micro-inhomogeneity is obtained accurately, then with the combination of subsequent forming and heat treatment technologies and the like, the marbled glass ceramics is obtained, so that the technology is easy to implement, and the influence of uncertainty on a product in a mixing process is reduced.