The present invention relates to a hydraulic transfer system concerning a technical scheme for transferring an arbitrary target to a reactor core of a research reactor, and more particularly, to a hydraulic transfer system for safely and remotely loading, withdrawing and cooling an irradiation target in an irradiation hole near the reactor core of the research reactor to minimize radiation exposure. To this end, requirements of designing the hydraulic transfer system include minimizing the reduction of neutron flux, minimizing radiation exposure of a researcher, enabling a remote operation control because it is impossible to enter a mechanical room while a reactor is operated, loading and withdrawing a target with the minimum force to prevent the target from being damaged, cooling the target irradiated even when the target is loaded or withdrawn, attenuating the radiation level to prevent water in a water tank from being radiated since the water in the water tank used for loading, withdrawing and cooling the target passes through the reactor core and returns to a working water tank in a polluted state, confirming a location of the target when the target is loaded or withdrawn, and sensing a leakage of water at the early stage to reserve the water in the water tank.COPYRIGHT KIPO 2016