Trilateral refers to the three towns in Shaanxi, Yansui Town, Ningxia Town and Guyuan Town in the Ming Dynasty. During the Ming Dynasty, in order to resist the invasion of Tatars, the imperial court set up Dingbian Yingcheng, Anbian Yingcheng and Jingbian Yingcheng in the corridor between Baiyu Mountain and Mu Us Desert, and the trilateral became a fixed regional term. At the end of the Qing Dynasty, the economy and trade of Anbian developed rapidly, dry docks were formed, and the "trilateral" was widely known. During the Anti-Japanese War, Trilateral, as the northern gate of the Shaanxi-Gansu-Ningxia Border Region, included all of Dingbian County, all of Jingbian County, part of Wuqi County, most of Yanchi County in Ningxia and part of Otok in Inner Mongolia. It is connected to Yuyan in the east, Ganshuang in the west, Celebration in the south, Desert and Sanqin Fortress in the north, with a vast territory and long sides.

The unique geographical location and historical strategic significance have formed a unique trilateral regional culture and national culture-trilateral culture, which has a profound precipitation and a long history. "Water comes from one mountain and returns to another, driving mules on three sides." In the Ming Dynasty, the Great Wall spanned the east and west, and the sites of Han tombs were widely distributed and deeply buried, with splendid folk art, and loess culture, grassland culture, frontier fortress culture, nomadic culture, desert culture, farming culture, Great Wall culture and folk culture blended together. The unique local culture such as paper cutting, storytelling, folk songs, prosperity and Taoist feelings in northern Shaanxi has become an important part of socialist culture.

"Water comes from one mountain and returns to another, driving mules on three sides." A high-pitched and melodious Xintianyou sings the "Trilateral" of Dingbian, Anbian (formerly a county, now a town) and Jingbian.

From Yangshao culture and Longshan culture sites discovered in Trilateral to many cultural sites in Shang, Zhou, Qin, Han, Tang, Song, Yuan, Ming and Qing dynasties, it is eloquently proved that residents have thrived in Trilateral since ancient times.

Generation after generation, they created three mellow rural customs.

However, the unusual historical background, unique geographical environment, the interweaving of various cultures and their different connotations make people living in the trilateral areas show obvious personalities in terms of food, clothing, housing and transportation, words and deeds, and treatment of people, which is "unusual with the surrounding areas and even the whole country", with thick colors and beautiful aura.

Here, the author wants to choose an angle to draw a cartoon-like outline of the trilateral customs and cultural phenomena from several aspects.

This kind of outline is probably a drop in the ocean, so my speech is not afraid of controversy, because it is a brick and a jade, and I am not afraid of criticism, because I expect perfection.