Second-order Bragg grating structure of 808 nm distributed feedback (DFB) semiconductor laser is designed and optimized. The grating fabrication process of 808 nm DFB semiconductor laser is introduced. The grating with a period of 240 nm is fabricated on GaAs substrate by holographic photolithography and wet etching. In the holographic photolithography system, mole grating and piezoelectric ceramic are used as fringe locked-in system to control optical path and lock fringes. Wet etching solution with 1:1:10 volume ratio of H3PO4, H2O2 and H2O is adopted to etch the grating for 30 s. Images of optical microscopy, scanning electron microscopy (SEM) and atomic force microscopy (AFM) show that the grating has a period of 240 nm, duty cycle of 0.25, depth of 80 nm, with perfect surface morphology, good fringe continuity and uniformity.