Vegetable oil asphalt cationic amide resin with dual functions of swelling prevention and sand control

The invention discloses a vegetable oil asphalt cationic amide resin. A preparation method comprises the following steps: (1) enabling vegetable oil asphalt and a diamine to react for 2.0 hours at 90DEG C and at normal pressure in the presence of a catalyst and under the protection of nitrogen; raising the temperature to 200 DEG C, and reacting for 2 hours under the pressure of 1.5 MPa; reducingthe pressure in a reaction kettle to normal pressure within 2 hours, vacuumizing to -1.0 MPa, and carrying out reduced pressure reaction for 1 hour to obtain an amide resin; (2) dissolving vegetable oil asphalt amide resin in xylene, dropwise adding excessive methyl iodide or iodoethane or chloroethane or bromopropane, and stirring for reaction at 90 DEG C; and cleaning a product with acetone, andevaporating to remove the solvent, thereby obtaining the vegetable oil asphalt cationic amide resin. The vegetable oil asphalt cationic amide resin has dual functions of swelling prevention and sandcontrol, can be used as a sw