Double Ninth Festival refers to the ninth day of the ninth lunar month, which is a traditional folk festival in China. The Book of Changes defines "nine" as yang number, and the two yang numbers of "nine nine" are heavier, so it is called "Chongyang"; It is also called "Double Ninth Festival", because both the date and the month conform to nine. Returning to the truth of 1999, the ancients thought that 1999 Chongyang was an auspicious day.

In ancient times, there were folk customs such as climbing to pray for blessings, enjoying chrysanthemums in autumn, wearing dogwood, offering sacrifices to gods and ancestors, and feasting on the Double Ninth Festival. So far, it has added the connotation of respecting the elderly, feasting on the day of Chongyang, and being grateful for respecting the elderly. Climbing mountains and enjoying autumn and giving thanks and respecting the elderly are two important themes of today's Double Ninth Festival.

According to the existing historical data and textual research, the source of the Double Ninth Festival can be traced back to ancient times. In ancient times, there were harvest festivals to celebrate heaven and Mars. "Lu Chunqiu Qiu Ji Ji" contains the activities of the ancients to offer sacrifices to the Heavenly Emperor and ancestors to thank them for their kindness during the harvest in September. This is the original form of the Double Ninth Festival as an autumn harvest sacrifice activity.

The Double Ninth Festival began in ancient times, took shape in the Spring and Autumn Period and the Warring States Period, spread in the Western Han Dynasty and flourished after the Tang Dynasty. The Tang Dynasty is an important period when traditional festival customs are mixed and shaped, and its main part has been passed down to this day. Chongyang ancestor worship has lasted for thousands of years and is an ancient folk custom with far-reaching significance.