The invention provides a method of rotating a column by 90DEG, and a rotation apparatus of rotating a column by 90DEG. The rotation apparatus includes at least one group of lifting points on a column, a first support block, a second support block, and a third support block wherein the lifting points are connected with a lifting rope; the first support block and the second support block support the column in the horizontal state; the second support block is flexible support; and the third support block supports the column when the column is in the vertical state. The method of rotating a column by 90DEG includes the steps: respectively placing the first and second support blocks under the edge of the front end and back end of the column; placing the third support block at the side surface of the second support block; starting the lifting rope to lift the front end of the column to enable the column to rotate until the column is in the vertical state and is located at the third support block by taking the edge of the back end as the fulcrum; and enabling the lifting rope to lift the column continuously until the column is separated from the second support block and the third support block. The method of rotating a column by 90DEG, and the rotation apparatus of rotating a column by 90DEG have the advantages of being simple in structure, being convenient to use, and effectively avoiding the safety hidden trouble brought by rotation of the column.