The invention provides a high light transmittance adaptive electromagnetic shielding device. The electromagnetic shielding device comprises a control module, an electromagnetic shielding module and amagnetic field detection module, wherein the electromagnetic shielding module comprises two shielding layers, the two shielding layers comprise conductive shielding films and multiple composite material shielding bars which are attached on the conductive shielding films, are mutually parallel and are connected in parallel with positive and negative pole leads, the two layers of composite materialshielding bars form an electromagnetic shielding grid, width and temperature of the composite material shielding bars are in direct proportion, the size of the electromagnetic shielding grid is adjusted through magnitude of a magnetic field control current between the positive and negative pole leads, and electromagnetic shielding performance is changed; the magnetic field detection module is usedfor detecting electromagnetic radiation intensity penetrating through the electromagnetic shielding module and converting electromagnetic radiation into a voltage sent to the control module, and thecontrol module is used for comparing the voltage with a preset threshold and adjusting a magnetic field control current according to the comparison result. The electromagnetic screen is advantaged inthat on the condition that electromagnetic shielding performance is guaranteed, and light transmittance of shielding materials is improved to a maximum degree.