The invention discloses a Low-carbon magnesia carbon 
brick with magnesia impregnated by 
tar and 
asphalt as an aggregate and a preparation method thereof. The low-carbon magnesia carbon 
brick comprisesthe following components by weight: 45 to 55% of a magnesia aggregate impregnated by 
tar and 
asphalt, 35 to 45% of unimpregnated magnesia, 3 to 5% of 
graphite, 0.5 to 1.5% of high-temperature 
asphalt, 2 to 3% of an 
antioxidant and 2.5 to 3.5% of a binder. The preparation method comprises the following steps: 1) carrying out impregnating so as to obtain the magnesia aggregate impregnated by 
tar and asphalt; 2) weighing the components with the desired weight; 3) premixing unimpregnated magnesia 
powder, high-temperature asphalt and the 
antioxidant to obtain mixed 
powder; 4) subjecting the magnesia aggregate and the unimpregnated magnesia 
powder to 
dry mixing in a mixing and 
grinding machine, then successively adding the binder, 
graphite and the mixed powder, and carrying out mixing and 
grinding to form a mixture; and 5) carrying out briquetting, molding and heat treatment so as to obtain the low-carbon magnesia carbon 
brick with the magnesia impregnated by tar and asphalt as the aggregate. The low-carbon magnesia carbon brick has the advantages of good 
thermal shock resistance, good resistance to 
slag erosion and great high-temperature strength, and is significantly prolonged in service life.