The invention discloses a plate explosion device which can improve the speed of a flyer, which is provided with a dielectric liner (1) with a bottom sealing and with a density of 0.9 to 2g/cm <3>. The bottom sealing is provided with a central hole (3) with a diameter smaller than the flyer (2), the flyer is arranged on the central hole (3) and an explosive cylinder (4) is positioned on the flyer (2) and is connected with an internal wall of the dielectric liner (1). The height of the dielectric liner (1) is higher than the height of the explosive cylinder (4), namely, 30 to 140mm. An externaldiameter of the dielectric liner is 2 to 3 times bigger than the diameter of the explosive cylinder (4). The plate explosion device reduces the sparse effect of the explosion products to the surroundings, therefore enlarge the pressure to the flyer by the explosion products, as a result, the flying speed is accelerated and the pressure of the flyer reduces from the center to the outer edge. Therefore, the flyer keeps plate flying and the impact received by the powder is even, which guarantees the powder calcinations or compounding quality.