In order to provide a scientific basis for preserving the Underground Palace in Jinling Dabaoen Temple, actual structural information of the Underground Palace was analyzed using engineering simulation software: ANSYS. Structural safety problems under various combinations of construction loads were noted. Then two different conservation designs involving the adding of sleeves and addling of sleeves and anchor rods were evaluated based on the conservation rules and the results of theoretical analysis. The structural performances of the two designs under four load combinations were analyzed comparatively by ANSYS. Finally, a conservation design plan for the underground palace in Jinling Dabaoen Temple was decided upon. The plan suggests adding both sleeves and anchor rods. The engineering parameters of the sleeves and anchor rods are also presented.