Abstract: An integrated device for grinding and polishing a diamond and a method thereof are provided. The integrated device for grinding and polishing the diamond comprises a base device and a grinding and polishing device, the base device comprises a base configured rotate around a Z-axis, the base comprises a fixture configured to clamp the diamond, the grinding and polishing device comprises a shaft disposed along the Z-axis, the outer polishing wheel surrounds the inner grinding wheel, the shaft drives the inner grinding wheel and the outer polishing wheel to rotate together, an upper and lower position relationship between the inner grinding wheel and the outer polishing wheel along the Z-axis is configured to be adjusted, and the diamond on the fixture is ground and polished by rotations of the inner grinding wheel and the outer polishing wheel, feeding, and a rotation of the base.