PURPOSE: To provide a cutting tool position control mechanism and its method by using an automatic grinding robot in which the cutting tool is chucked to an arm type robot and contacted and operated to a rotary grinding jig at a necessary angle.

CONSTITUTION: A sensor 31 to detect the edge line position of a cutting tool 7, a sensor 32 to detect the curve near the edge line of the cutting tool, a data input device to input the data detected by the sensors 31 and 32, and an operation device 34 are provided, and by collating the operation result from the operation device 34 and a standard value being input to a robot control device 35, the grinding is carried out by an automatic grinding robot while correcting the edge line position and the curving data of the cutting tool 7. Such a cutting tool position control mechanism and its method are provided.