Glass straight line edging machine is used for grinding and polishing straight edges or 45deg.angles on flat glass of different sizes and thickness. Coarse grinding, refine grinding, polishing, and angle-making can be completed in a procession. Speed can be widely adjusted by its step less regulator. Speed alteration is very smooth. In grinding operation, feeding and operation speed can be adjusted at random. Front rails can be adjusted to fit varied thickness of processed glass. It has feature with high precision, easy handling and high efficiency.