Compared with the cylindrical grinding, internal cylindrical grinding mainly has the following characteristics: A grinding accuracy is difficult to control. Because the CBN Grinding Wheelcontact with the workpiece area, heat, cooling conditions are poor, prone to thermal deformation work; especially as elongate shaft wheel, rigidity, easy to produce bending deformation, causing cylindrical (inner conical) Error . Thus, the general need to reduce the grinding depth, increasing the light grinding times. Two large grinding surface roughness Ra. When internal grinding wheel speed is generally not more than 20000r/min As wheel diameter is small, difficult to reach its line speed cylindrical grinding 3050m / internal grinding roughness Ra value is generally 1.60.4μm 3 low productivity. Because the wheel diameter is small, wear fast, easy to wash away debris coolant end, wheel easy to plug, it requires frequent repair or replace the wheel. Additionally, to ensure accuracy and surface roughness, is necessary to reduce mill grinding depth and increasing the number of light, are bound to affect productivity.