A high precision angular driving device was developed for a Large-Scale and High Accurate Turntable( its positioning accuracy should be less than 0.5″) for calibration and test of cameras.The whole structure of the turntable was introduced, and the principle and structure of the developed angular driving device were given in detail.By using a new angular displacement conversion mechanism, the angular driving device could convert the straight-line displacement into a angular displacement to obtain a high angular resolution.Meanwhile, the angular micro driving device scarcely generates the axial force or radial force to influence on the axis accuracy in driving turntable.Furthermore, a new positioning method combined coarse and fine positionings was proposed to improve the positioning accuracy, in which a torque motor was used for coarse positioning and the angular driving device for fine positioning.Finally, the angular resolution of the angular driving device was calculated and verified, results show that it is superior to 0.08″ and can meet the requirement of the turntable for positioning accuracy.