The invention relates to a high-efficiency chlorine leakage scavenger and a preparation method thereof, and aims at solving the problem of poorer removing effect of chlorine leakage in the prior art. The high-efficiency chlorine leakage scavenger is prepared from the following components in percentage by mass: 65 to 90 percent of main reactant, 0.5 to 25 percent of auxiliary reactant and 0.5 to 10 percent of moisture-proof dispersant. The main reactant is selected from elements, compounds and/or a mixture of iron, barium, aluminum, magnesium, zinc and carbon; the auxiliary reactant is selected from elements, compounds and/or a mixture of silicon, potassium, and sodium; the moisture-proof dispersant is prepared from hydrophobic silicone oil, water absorbent resin, molecular sieves, bibulous silica gel or organic solvents. By adopting the technical scheme of the high-efficiency chlorine leakage scavenger and the preparation method thereof, the problem is better solved; the high-efficiency chlorine leakage scavenger can be used for arresting leaked chlorine.