The invention relates to a heat pipe-based passive after-heat removal system of a spent fuel pool. The heat pipe-based passive after-heat removal system is characterized in that a plurality of baffles are arranged around the interior of the spent fuel pool, the heights of the baffles are lower than the height of the spent fuel pool, a plurality of evaporating end heat pipes are arranged between the outer sides of the baffles and the inner wall of the spent fuel pool and are divided into a plurality of groups, outlets in the top ends of each group of evaporating end heat pipes extend out of the spent fuel pool and are connected with inlets of one path of ascending connecting pipes, outlets of the path of ascending connecting pipes are connected with inlets in the tops of one group of condensing end heat pipes comprising a plurality of condensing end heat pipes, outlets in the bottoms of the group of condensing end heat pipes are connected with an inlet of one descending connecting pipes, and an outlet of the descending connecting pipes extends into the spent fuel pool and is connected with inlets in the bottoms of one group of evaporating end heat pipes. According to the heat pipe-based passive after-heat removal system, the spent fuel pool is cooled by adopting the heat pipes, low-temperature difference high-efficiency heat exchange is realized through phase change heat exchange of working mediums of the heat pipes, the dependence on a power supply and the personnel is radically eliminated by virtue of density difference natural circulation drive, and the long-term passive high-efficiency heat exchange cooling of the spent fuel pool is realized.