A safety shackle includes a U-shaped shackle body and a bolt shaft. Two ends of the opening of said shackle body are each provided with a screw hole, and the front end of the bolt shaft is reached the screw hole at one end of the shackle body and screwed into the screw hole at the other end thereof. The screw size of the screw holes cooperates with that of the bolt shaft. Preferably, said bolt shaft is a regular bolt. The frond end (L5) and the rear end (L6) of said bolt shaft have the same screw size. Alternatively, the screw size of the frond end is less than that of the rear end. Further, the length (L4) of the bolt shaft is equal to or less than the outside width (L3) of the two ends of the opening of said shackle body. With the invention, the bolt shaft would not fall off even if the screw at one end get loose or the bolt shaft breaks at its center, so as to make the connection safer and more reliable.