The invention discloses a high-strength ceramic brick and a preparation method thereof. The ceramic brick is prepared from the following raw materials in parts by weight: 40-60 parts of yellow sand, 30-50 parts of barite, 15-25 parts of dolomite, 10-20 parts of volcanic rock, 20-30 parts of zirconite, 5-15 parts of mullite, 4-12 parts of blast furnace slag, 16-28 parts of modified clay, 7-14 parts of sea mud, 11-19 parts of a silica micro-powder, 8-16 parts of a waste brick powder, 3-9 parts of tricalcium phosphate, 4-8 parts of barium carbonate, 2-5 parts of nano silicon carbide, and 3-6 parts of nano alumina. The prepared ceramic brick has high strength, has the breaking strength of not less than 1050 N and the rupture modulus of not less than 30 MPa, is anti-knock, anti-cracking and non-friable, and enables the service life to be significantly improved.