The electric spindle is a set of components, which includes electric spindle main body and its accessories: electric spindle, high frequency and frequency conversion device, oil mist lubricator, cooling device, built-in encoder and tool changer, etc. The rotor of the electric motor shall directly serve as the spindle of machine tool; shell of the spindle unit is the motor base. We realize the integration of electric motor and machine tool spindle with the support of other spare parts.