Abstract: A fixing device for the windshield of a safety helmet includes a windshield having its left and right end provided with a projection with projecting wings, a projecting rib and a slide block. A helmet shell is fixed with a base plate respectively at the opposite ends of its window. Each base plate is provided with a corrugated edge near the annular recess base, and a slide groove for receiving the slide block with a slidable lip block in its intermediate portion of a groove. In assembling, the windshield is slightly moved for a little angle, with projecting wings of the projection fitting in the two notches of the helmet shell and fixed by the lip blocks to keep the windshield immovable in place, convenient to assemble and use the windshield with the helmet shell.