Method for realizing three-axis machining of normal plane of glass measuring instrument

The invention provides a method for realizing the three-axis machining of a normal plane of a glass measuring instrument, which comprises the following steps: (1) dividing the glass measuring instrument needing machining into small blocks, wherein each small block comprises an upper-edge long contour line L1 and an upper-edge short contour line L2; L1 is 30 to 50 percent as long as L3 and L2 is 20 to 40 percent as long as L4; the upper-edge long contour ling L1 forms an included angle of 90 degrees with the upper-edge short contour line L2; L3 is the long side of an analogue block and L4 is the short side of the analogue block; and both L1 and L2 are longer than or equal to 500mm; (2) turning over the divided small blocks 180 degrees and machining the small blocks with a three-axis machining centre; and (3) splicing the machined small blocks into the glass measuring instrument. The method of the invention has the advantages of simplicity, practicability, no need of expensive five-axis linkage machining centre