The utility model discloses a terrace buried type underground nuclear power station, comprising a nuclear island and a conventional island, wherein nuclear buildings of the nuclear island are arranged in nuclear island underground caverns of a mountain, the conventional island is arranged on a terrace platform at the upper part of a side slope of the mountain, the nuclear island underground caverns are buried in the mountain relative to the conventional island. The terrace buried type underground nuclear power station of the utility model is suitable for the terrain environment that there is no suitable platform at the outer side of the side slope of the mountain, and there is a large terrace platform on the upper part of the side slope or it is easy to artificially excavate the upper part of the side slope to form a large platform, thereby providing a feasible general layout for construction of the underground nuclear power station; compared with a ground nuclear power station, the main process system does not need to be greatly adjusted, thereby reducing research and development difficulty of technology of the underground nuclear power station; nuclear island plants are laid in different underground caverns, thereby ensuring that the present underground engineering technology can meet the requirement of the nuclear power station for laying the nuclear buildings under the ground.