Abstract: To accelerate the simulation of parallel finite-difference time-domain(FDTD), this paper proposes a new numerical acceleration technique based on the streaming SIMD extensions(SSE), and gives an implementation on Intel T2300 platform, and then puts forward a three-level data parallel algorithm based on message passing interface(MPI), OpenMP and SSE.The numerical experiments for the electromagnetic radiation problems have demonstrated the high efficiency of this new technique, and can achieve an acceleration rate of 2.62.The result shows that this technique dramatically improves the computing efficiency without any extra hardware investment.