The invention discloses a steel plate for a shield and a preparation method thereof and belongs to the technical field of steel plate production. The steel plate comprises the chemical components of, by weight, 0.35-0.43% of C, 0.20-0.40% of Si, 1.2-1.5% of Mn, 0.02-0.04% of Ti, 0.01-0.06% of Al, 0-0.4% of Ni, 0-0.5% of Cr, 0.01% of P or the less, 0.004% of S or the less, 0.008% of N or the less, 0.0010-0.0030% of B and the balance Fe and inevitable impurities. According to the steel plate for the shield and the preparation method thereof, the strength grade of the steel plate reaches 1500 MPa, good cold forming performance and excellent bulletproof performance are achieved, and the steel plate and the preparation method thereof are suitable for production of the shield.