This study investigates an optimal design for reducing the unexploded rate of submunitions released from a cluster bomb. We attempt to identify the main factors that cause the unexploded submunitions and find ways to solve them. First, an M&S analysis is performed to determine the cause of the unexploded submunitions, based on which a design for the body shape of a submunition applied with a method of protecting the fuse is implemented. In addition, we attempt to improve the operational performance of the submunition fuse with an improved shape. Through this process, a design is produced and simulated to prove its validity.