The machine can cut irregular (cylinder, polygon, etc.) metallographic sample materials, so as to observe metallographic and petrographic structure of the materials. The machine uses dual-housing fully-enclosed structure, ensuring absolute safety in cutting samples. Its cooling device uses well-formulated cooling liquid to take away the heat during cutting, thus preventing the damage caused by overheat of the sample. The cutting sample can be regulated its angles, which prevents tiny burning of sample surface when the sample is cut down, and also increases cutting section and enhances utilization ratio of abrasive disc. The machine, easy to use, safe and reliable, is an indispensable sample preparation equipment for the labs of plants, research institutes and universities and colleges.