The invention discloses an electromagnetic field shielding performance testing system for dust type dielectric materials, and relates to the technical field of dielectric material electromagnetic field shielding testing. The electromagnetic field shielding performance testing system comprises an electromagnetic wave signal source, high frequency signal lines, a power amplifier, an antenna, an electromagnetic shielding box, a dust type dielectric material box and an electromagnetic field tester. The electromagnetic wave signal source is connected with the power amplifier through one high frequency signal line, and the power amplifier is connected with the antenna through one high frequency signal line. A stirring fan is arranged in the dust type dielectric material box, and the dust type dielectric material box is fixed at an opening in one side of the electromagnetic shielding box. The electromagnetic field tester is connected with an electromagnetic shielding probe through a coaxial cable, the electromagnetic shielding probe stretches into the electromagnetic shielding box, and the electromagnetic shielding probe and the dust type dielectric material box are placed at the opposite positions. By means of the electromagnetic field shielding performance testing system for dust type dielectric materials, the electromagnetic shielding effectiveness of dust can be tested, and theoretical and technological support is provided for preparing composite electromagnetic shielding materials; the structure is simple, operating is convenient, and implementation is easy.