The invention provides a slow-release antifreezing material for asphalt pavements and a preparation method thereof. The preparation method comprises the following steps: proportionally, sufficiently and evenly mixing chloride and a corrosion inhibitor, granulating, coating with a slow-release agent, screening and drying to obtain the slow-release antifreezing material for asphalt pavements. After the slow-release antifreezing material and asphalt admixture are mixed and made into an asphalt pavement, the freezing point of the pavement in winter can be lowered so as to effectively prevent the pavement from forming black ice, so that the asphalt pavement has the function of actively avoiding icing at -10-0 DEG C. The slow-release antifreezing material for asphalt pavements can lower the hazard of ice and snow to the road in winter, lower the snow-melting and deicing cost of the road by lowering the spreading amount of the traditional snow melting agent, and lower the corrosion to the pavements and bridge steel bars and the hazard to the field crops and greening plants on both sides of the road.