The invention discloses a modified catalytic oil slurry and a method for preparing a road asphalt by using the modified catalytic oil slurry, wherein the modified catalytic oil slurry comprises 95.0-99.9% of catalytic oil slurry and 0.1-5.0% of a modifier, and the modifier is one or a plurality of materials selected from condensed aluminum phosphate and a silicon phosphate curing agent. Accordingto the present invention, the temperature-sensing property and the anti-aging property of the road asphalt obtained by blending the modified catalytic oil slurry and matrix asphalt are significantly improved.