Disclosed is a grinder transmission device, comprising a first transmission shaft (2) for driving an inner grinding wheel to rotate, a second transmission shaft (3) for driving an outer grinding wheel to rotate, a main shaft (1), a first gear (5), a second gear (6), and a third gear (7), wherein an upper part of the first transmission shaft (2) is fixedly connected with the first gear (5), an upper part of an outer wall of the second transmission shaft (3) is provided with a transmission tooth (31), the second gear (6) is coaxially connected with the third gear (7) in a fixing manner, a bottom part of the main shaft (1) is meshed simultaneously with the first gear (5) and the second gear (6), the third gear (7) is meshed with the transmission tooth (31) on the upper part of the outer wall of the second transmission shaft (3), which can realize simultaneous reverse rotations of the inner grinding wheel and the outer grinding wheel, improve the grinding effect, reduce working intensity of an operator, and prolo
