There are various applications of permanent magnet brushless DC motor (BDCM). They offer a number of attractive features and could meet the requirements coming from new generation satellites such as high attitude precision, high maneuver capacity and high stability. Therefore, high speed magnetically suspended inertia devices using BDCM is becoming the best choice for inertia actuators. In this paper, design principles including hollow cup BDCM electromagnetic design method and optimized structural design methods are reviewed. Also, the control methods of high speed BDCM used for magnetically suspended flywheel (MSFW) including PLL method, double mode control method and current restraint method are reviewed. The worldwide applications of high speed BDCM in magnetically suspended inertia actuators are considered.