With the continuous exploration of the universe and astronomy’s development, the telescopes are bigger and bigger. Horizon structure is widely used in the modern large telescopes rack, which carries dozens, even thousands of tons of the rotary parts and demands high accuracy and good stability. Therefore, it is one of the key technologies for large telescope to develop the precision support technology integrated direct drive with large load, high stiffness, low friction , even frictionless. Magnetic suspension bearing has not only the advantage of non-contact, no friction, high rigidity, high precision, low power, low mechanical assembly requirements, but also is integrated with the driven torque motor, which simplifies the structure, reduces the cost. This paper explores one kind of active bias magnetic suspension bearing

integrated with direct drive technology based on multidisciplinary design optimization (MDO), which provides a new choice and view for the modern large astronomical telescope tracking system.