The invention discloses a pulse detonation fracturing device capable of being suitable for an ultra high-temperature high-pressure well. The pulse detonation fracturing device comprises a high-temperature high-pressure igniter, a fracturing gun barrel, a high-temperature resistant waterproof gunpowder, a central gun barrel system and a gun breech or connectors, wherein the fracturing gun barrel is provided with a pressure relief hole; the central gun barrel system is a main pressure-bearing body and comprises a thick-wall gun barrel, a drilling bullet, a detonating cord and a bullet rack pipe, and the central gun barrel system can not only bear a high-temperature high-pressure environment inside a well, but also reliably ignite the high-temperature resistant waterproof gunpowder. The pulse detonation fracturing device disclosed by the invention supports the ultra high-pressure environment inside the well by utilizing the thick-wall gun barrel and ignites the high-temperature resistant waterproof gunpowder by utilizing detonation waves generated in such a way that a hole is drilled in the thick-wall gun barrel by the drilling bullet; and according to the invention, the high-temperature resistant waterproof gunpowder is filled in the fracturing gun barrel and used for a high-temperature high-pressure well with the depth being more than 5000m and the pressure being more than 70MPa. The pulse detonation fracturing device disclosed by the invention can be in series connected into a fracturing pipe string by adopting the connectors to be used for the fracturing, the plug removal and the yield increase of a long-well section and large-span or horizontal well.