This paper presents the development of unmanned Surface-Underwater combined platform. Using a tether cable, the UUV(Unmanned Underwater Vehicle) can be connected to the USV(Unmanned Surface Vehicle) for reliable power supply, and the data can be delivered to USV and operation center in real time. The SBL(Short Base Line) transponders are attached to the USV body, so the UUV location can be determined in real time. UUV can launch and recover through winch system included in USV and collect target data using image sonar or underwater camera. Data collected by the two platforms can be transmitted to the operation center in real time via RF communications. In addition to the manual mode in which the operator directly operates the platform, also it is equipped with a waypoint tracking algorithm that enables autonomous driving to the target location and a dynamic positioning algorithm that maintains the working position of USV during the operation of the UUV.