The invention relates to the field of electric communication equipment, in particular to a shielded power grid protective cabinet. The cabinet comprises a cabinet body, a cabinet door, a voltage stabilizer, a breaker, a contactor, a transformer, a relay, a current Hall transformer, a switch power supply, a digiboard, an analog board and a wiring terminal, wherein the board structure of the cabinet body and the cabinet door is formed by a steel plate layer, a foaming plastic layer, a metal shielding layer, a flexible foam layer and an insulating shell layer successively from inside to outside, wherein an air conditioner is arranged on the top of the cabinet body, and an insulating earthing lead wire is arranged on the bottom of the cabinet body. The metal shielding layer is added between the cabinet body board and the cabinet door board, so that electromagnetic radiation and electromagnetic leakage can be effectively prevented, positioning reliability can be remarkably improved, production efficiency can be improved, and system safety and quality safety of power supply can be ensured.