The invention provides a measuring block for establishing a slope coordinate system quickly. The measuring block comprises a slope area on one side and a tool setting area on the other side; the slope area consists of a V-shaped groove and a rectangular groove which is positioned in the bottom of the V-shaped groove; the symmetrical planes of the V-shaped groove and the rectangular groove are overlapped; the two side surfaces of the V-shaped groove form 90 degrees; the machining precision is required to be within 90 degrees +/-10 minutes; the upper limit of the surface roughness of the two side surfaces of the V-shaped groove is 1.6 mu m; the depth of the rectangular groove meets the requirement that the intersecting line of the extending surfaces of the two side surfaces of the V-shaped groove is positioned in the rectangular groove; the tool setting area is a rectangular area; the symmetrical planes of the rectangular area are overlapped with the symmetrical planes of the V-shaped groove and the rectangular groove; the rectangular area is provided with three tool setting surfaces; the upper limit of the surface roughness of the three tool setting surfaces is 1.6 mu m. By adopting the measuring block for establishing the slope coordinate system quickly provided by the invention, the preparation time for performing repeated clamping, aligning and trial cutting on a workpiece can be shortened, so that the operation is simple and quick; the machining position precision is improved; the quality risk caused by a tool setting error because of the deviation of a coordinate system is reduced, so that the production capacity of high-efficiency numerical control machining equipment is played better.