Abstract: he divergence angles of the single-mode Gauss beam generated by GaAlAs SDL-5400 LD laser in the perpendicular directions are not equal, and there is astigmatism in the beam. In order to obtain the circular light spot with common beam waist, a collimating and shaping module with two semi-cylinder perpendicular lenses and a pair of prisms was designed according to the complex parameterand ABCD-law. The far-field divergence angle of the collimated and shaped LD laser beam, which was calibrated with CCD, was 0.53mrad in the sagittal direction and 0.64mrad in the meridional direction.