It was first built in 1087. Legend has it that Jigzun Xerab Qoinnyai asked for advice from his teacher Lhodain Dorje Wangqug on the selection of the site for a monastery. The latter hurled his staff, as if shooting an arrow, and the staff fell where the site of the monastery was established. The staff fell on the tender leaves of canola; thus inheriting the name of Xalhu, meaning new growth of tender leaves. In 1329, the monastery was destroyed in an earthquake. The emperor of the Yuan Dynasty at the time granted great wealth for the monastery to be rebuilt. In 1333, Master Purdain Renqen Zhuba took charge of the project. He invited many Han Chinese craftsmen from inland provinces and had the monastery rebuilt in a unique architectural style. Xalhulhakang, the main building of the monastery, has an arch-like ceiling, glazed tiles and bells hanging on the roof, a complete imitation of the style of inland temples. Yet it still retains the characteristics of a Tibetan monastery with red mud-and-stone walls and interconnecting halls. It can be considered a perfect combination of Han and Tibetan architectural styles. The murals in the halls are rich and lively with a strong Yuan-dynasty flavor. The images of Buddha are particularly refined and special. Among the relics housed in the monastery are eight precious Yuan-dynasty proclamations of the Pagba time, besides religious implements, Buddhist scriptures on pattra, sacrificial utensils and tangka painting scrolls.

The Xalhu Monastery is famous for its four treasures. The first is the printing plate of Buddhist scriptures, which is made of 108 blocks of wood by Abbot Purdain. It is said to be able to last one thousand years, yet it cannot be broken apart because it is impossible to arrange them in their original positions. Master Purdain had written many works in his life; the most well-known are Dangyur and History of Buddhism by Master Purdain in 1322. The second treasure is the holy jar made of bronze.It is claimed that inside the jar is the clearest water in the world, which is replaced every 12 years. The mouth of the jar is covered with red cloth. Legend says that the water can cure diseases and wash away dirt and filth. The third is the stone tablet with six characters. It is said that the tablet bore the six characters when it was unearthed during the construction of the monastery. Its edge is engraved with four exquisite small towers. The fourth is the huge basin-shaped stone in which the Living Buddha Jigzun Xerab Qoinnyai, who built the monastery and Pandit Gonggar Gyaincain of Sagya, had once washed their faces. It is said that the stone basin would not overflow even if filled with water on a rainy day.