When the sun is sharp, especially the solar flare, sensitive X-rays, ultraviolet rays and so on from the sun, make the D layer of the ionosphere thicker, the which, by improving the long wave, however, the short wave reflected by the E and F levels has attenuated due to the strong absorption by the D levels. Some time later, the energetic particle produced by the solar flare arrives on the earth, yes directs towards the geomagnetic poles due to the Earth's magnetic field, thus affecting the ionosphere and causing interference in high-latitude radar and radio communications.