Table top torsion angular displacement measuring device

The invention discloses a table top torsion angular displacement measuring device which comprises an inner supporting column, a measured table top is installed at the upper end of the inner supporting column, a twenty-four-face prism is installed at the upper end of the measured table top, and a grating drum installed on the inner supporting column is arranged at the lower end of the measured table top. A collimator aligned with the twenty-four-face prism is arranged on one side of the table board to be measured, an outer supporting column is arranged on the outer side of the inner supporting column, and a reading head matched with the grating drum is installed at the upper end of the outer supporting column. According to the invention, the collimator is aligned with the angular displacement of the twenty-four-sided prism measuring table surface on the measured table surface under the torque state, and the grating angle measuring element is additionally arranged to measure the angular displacement of the supp