Modified asphalt and preparation method thereof

The invention relates to the technical field of modified asphalt, in particular to modified asphalt and a preparation method thereof. The preparation method of the modified asphalt comprises the following steps: S1, mixing petroleum asphalt and rubber powder, and performing high-speed shearing to obtain rubber asphalt; s2, mixing the rubber asphalt and bio-oil at 120-150 DEG C, and performing high-speed shearing to obtain modified asphalt; in the modified asphalt, the content of the rubber powder is 15 to 18 weight percent, and the content of the bio-oil is 5 to 10 weight percent. According to the preparation method of the castor oil-based bio-oil and rubber powder composite modified asphalt, swelling of the rubber asphalt can be promoted, so that the rubber asphalt has good stability, good high-temperature performance, good low-temperature performance and good construction workability; and the aging of the bio-oil light component in the preparation process of the castor oil-based bio-oil and rubber powder co