Gear form grinding technology is widely used in the process of gear manufacturing. Grinding wheel dressing is the key technology of gear form grinding process. In this paper, several different grinding wheel dressing methods and the corresponding diamond roller dressing device are simply introduced. The technical parameters of grinding wheel dressing are respectively analyzed, including dressing speed ratio, overlap ratio, dressing depth and axial speed. The experimental tests of gear form grinding are carried out to investigate the effects of dressing parameters on the grinding process. The results of analysis and manufacturing tests can provide the reliable basis for diamond roller dressing in gear form grinding machine tools.