The invention relates to a high-efficiency clean Al-Ti-B refiner and a preparation method thereof, belonging to the technical field of refiners. The high-efficiency clean Al-Ti-B refiner comprises the following components in percentage by mass: 3.0-6.0% of Ti, 0.6-2% of B and the balance of Al. The phase composition comprises alpha-Al, TiAl3 and TiB2. The preparation method comprises the following steps: weighing B2O3, TiO2, aluminum powder and aluminum ingot according to requirements, wherein the TiO2:B2O3:Al powder ratio is (2.8-3.2):(3.5-4.2):(4.7-5.2)(mol), and the purity of the aluminum ingot is 99.9%; evenly mixing the TiO2 and B2O3, and heating at 300 DEG C for two hours; mixing the heated powder and aluminum powder, putting the mixture in a mold, and pressing into a block; melting the aluminum ingot by heating, and covering cryolite; and heating the melt, pressing into the block, stirring to react, pressing in C2Cl6, refining, removing slag, and casting. The invention utilizes low-cost raw materials; the dimension of the prepared TiB2 is 1 mu m; and the dimension of the TiAl3 is 3-30 mu m, and the TiAl3 is distributed uniformly.