The invention discloses a transformer oil discharge sealing device and a transformer. The transformer oil discharge sealing device comprises a transformer main body and a U-shaped pipe. One end of theU-shaped pipe is bent upwards to form a bent section. The bent section is fixedly connected with the transformer main body. When the transformer discharges the oil, the gas cannot reversely flow intothe transformer. Therefore, the sealing effect needed by the transformer during oil discharging can be effectively achieved. The device is simple in structure and the oil discharging efficiency is not affected at all.