The utility model discloses a sealing device of a shield tunneling machine and the shield tunneling machine. The sealing device of the shield tunneling machine is arranged on the tail shield of the shield tunneling machine and comprises a sealing air bag and a supporting and protecting plate, wherein the sealing air bag is annular as a whole and arranged on the surface of the outer circumference of the tail shield; the supporting and protecting plate is arranged on the surface of the outer circumference of the tail shield and next to the sealing air bag, and the supporting and protecting plate is arranged in front of the sealing air bag so that an annular shape can be formed. When the sealing air bag of the sealing device of the shield tunneling machine is not inflated, the sealing air bag is arranged in a containing groove in a shrunken mode, the sealing air bag is covered with the supporting and protecting plate, and therefore the sealing air bag can be protected against wear. After the sealing air bag is inflated, the space between the tail shield and a tunnel soil body is filled with the sealing air bag so that good sealing can be formed, slurry such as concrete can be effectively prevented from flowing back and adhering to the shield body, friction force between the tail shield and the soil body can not be increased suddenly, and the shield tunneling machine can move forward without great difficulty; meanwhile, the sealing air bag can keep a stable air pressure value between the shield body and the tunnel soil body, and the soil body can be supported to a certain extent.