The utility model discloses a portable transformer sealing device with a protection function. The device solves the problem that an existing device threatens personal safety of workers, and is characterized by comprising a short circuit clamp, a short circuit wire, a grounding wire and grounding connection device and a sealing tool, the short circuit clamp is connected with a transformer high-voltage side pile head, one end of the short circuit wire is connected with the short circuit clamp, and the other end of the short circuit wire is connected with the grounding wire and grounding connection device; the sealing tool comprises a sealing wire, sealing lead, a sealing lead hole and an operating rod, two round holes are formed in the two sides of a jaw of the short circuit pliers, and thesealing wire penetrates through the round holes of the three short circuit pliers, then penetrates through the sealing lead hole and is fixed in the sealing lead through extrusion of the operating rod. The transformer sealing device is provided with the grounding protection device, so that the transformer can be in a grounding state all the time when a worker seals the transformer, the worker is protected, and the transformer can be quickly sealed.