A new method of directional processing for CdGeAs2 (CGA) crystal was presented. Based on the cleavage plans of CGA single crystals combined with standard pole figure and the X-ray diffraction pattern, the c axis of the single crystal can be quickly obtained by this new method. Using this method combined with directional cutting, grinding and polishing, the initial SHG devices of CGA crystals grown by an improved vertical Bridgman method through spontaneous nucleation have been fabricated. Its phase matched angle θm is 33.58o, azimuth angle φ is 0o, and the device size is 5 mm×5 mm×8 mm.