The invention discloses a high-strength road pavement brick and a preparation method thereof, and relates to the technical field of building materials. The high-strength road pavement brick is prepared from the following raw materials in parts by weight: 40 to 60 parts of cement, 20 to 35 parts of steel slag, 18 to 26 parts of modified kaolin, 8 to 14 parts of steel fiber, 10 to 16 parts of modified micro-silicon powder, 4 to 8 parts of sodium tripolyphosphate, 1 to 6 parts of polyamide, 4 to 12 parts of sodium lignin sulfonate, 2 to 10 parts of potassium tartrate, and 3 to 7 parts of an enhancer. The preparation method of the high-strength road pavement brick comprises the following steps of preparing mixed powder, preparing a mixed solution, mixing, pressing and forming, and curing. Theroad pavement brick has the advantages that the strength is very high, and the mechanical property still can be maintained under very adverse conditions.