His reign ended with the collapse of the Western Xia as forces of the Mongol Empire under Genghis Khan overran and conquered it following the defiance of earlier emperors.
The Mongols gave Li Xian the name Shidurghu (Mongolian:ᠱᠢᠳᠤᠷᠭᠤ, Chinese: 失都兒忽), meaning "simple, right, just", and in 18th century European sources he is referred to as Schidascou or Shidaskû from his Mongolian name.
However, Zhongxing suffered from a massive earthquake, which resulted in pestilence and food shortage.
In August 1227, the Mongols killed Li Xian and his entire family out of fear that the Western Xia would rebel again over the death of Genghis Khan.
After the fall of the Western Xia, the Mongol army discussed the massacre of the city, but finally, under the strong advice of the Mongol general Tsa Han (Chinese: 察罕), who was from Tangut, the people of Zhongxingfu were prevented from being massacred, and Tsa Han then went into the city to pacify the people and soldiers therein, so that the people left behind by the Western Xia could be preserved.