Air Defense System requires fast movement of the turret to detect and attack the flying target of enemy. In order for the air defense system to operate accurately and properly, it is necessary to optimize the design of the motor brake system. The air defense system that is not designed properly has possibility of low performance of the gun turret and environment of operators. The previous air defense system had such flaw in its design and it caused much noise and current in the operation of the turret. In order to resolve this flaw, we changed the position and design of the components of the motor brake system to reduce load and achieved the 62.5% reduced current and 40% reduced noise of the motor brake system compared to the previous design.