The utility model discloses a multifunctional relay protection testing device protecting box which comprises a box body and a support. The box body comprises a bottom plate, a side plate, a top plate, a front door and a back door. Trundles are arranged below the bottom plate. A pulling rod is arranged at the front end of the bottom plate. A handle is arranged at the front end of the pulling rod. A hand lifting handle is arranged on the side plate. A door shaft is arranged at the bottom end of the front door. The front door is connected with the bottom plate through the front door shaft in a coupling mode. A buckling lock is arranged at the top end of the front door. A buckling piece is arranged at the front end of the top plate. The front door and the top plate are buckled together. The back door is provided with a rotatable power supply blocking plate and a radiating hole. A support is arranged above the top plate. A supporting plate is arranged at the upper end of the support. An anti-vibration partitioning layer is arranged in the box body. The multifunctional relay protection testing device protecting box is suitable for a relay protection testing device and a relay protection testing system formed by a computer, frequent carrying of the relay protection testing device is convenient, a radiating function is good, and testing wiring and storing are convenient.