This paper proposes an optimal control algorithm for Zero-Voltage-Switching (ZVS) operation of the clamp-switch bidirectional DC-DC converter (CL-BDC) using micro controller unit (MCU). The CL-BDC uses the clamp switch to operate ZVS. The clamp switch of the CL-BDC divides the inductor current from input and output. The minimum of the inductor current is maintained to satisfy ZVS condition by the clamp switch in this topology. By operating ZVS, the switching loss is reduced. As a result, the efficiency of the entire system is increased. In addition, the separation of the inductor current can reduce the ripple of the inductor current and extend the life of the capacitor. Accordingly, the clamp switch control algorithm is important to improve the system efficiency. The proposed control algorithm is verified in PSIM simulation and the prototype of the 1-kW ZVS CL-BDC.