Geomantic omen began to be associated with folk witchcraft in Qin and Han dynasties, which was related to the fate, divination and phase of the five arts. It is also said that it basically constitutes the divinatory symbols derived from the Book of Changes, which are divided into folk beliefs such as keeping the well and the kitchen, and keeping the house in the shade. Its main schools are trichotomy, trichotomy and nine planets method. The word Feng Shui was first seen in Guo Pu in the Jin Dynasty: "Qi dispels by the wind, and the boundary water stops. The ancients gathered to make it last forever, and the deeds stopped, so it was called Feng Shui. " The theoretical background of folk belief The main theory of "folk belief in Feng Shui" is based on the traditional theory of Yin and Yang. They borrowed from the earliest Confucian classic Zhouyi in China, which was full of philosophical thoughts, and joined Taoism (advocating the unity of form and spirit, keeping form with spirit and nourishing spirit with form), Buddhism (advocating karma and reincarnation), witchcraft (advocating the influence of gods on people's luck) and astrology (advocating the influence of stars on people), which promoted the development of Feng Shui. Everything originates from heaven and earth, that is, people and all living things are the products of the interaction between heaven and earth. "Tai Chi gives birth to two instruments, two instruments give birth to four elephants, four elephants give birth to eight diagrams, and eight diagrams overlap into sixty-four hexagrams". Taiji is the primitive state, two instruments are heaven and earth, and four images are the weather of the four seasons; It is called the sun (long sunshine is like summer), the moon (short sunshine is like winter), less sunshine and less yin, and gossip are eight directions, which come from the simple philosophy of the Book of Changes, that is, everything in the universe has the same information, the same procedure and the corresponding rhythm. The unified field of the universe. This is the unity of heaven, earth and people. To put it simply, the theory of geomantic omen is mainly based on the theory of the rise and fall of Yin and Yang in metaphysics, with the help of heaven (universe, sun, etc.). ) and the earth (earth, geographical environment) and people (where people live and bury) and time (the rise and fall of heaven and earth, the birth and death of everything). Unfortunately, it was later rigidly matched by alchemists with various so-called five-element coping strategies, forming a folk belief of praying for good luck.