In fact, Meng Po has already mentioned in Shan Hai Jing: "The emperor's two daughters swim in the middle of the river and will go in and out with the wind and rain, so they are called Meng Po with the emperor's daughter." Visible in ancient times, Meng Po has a prototype. Later, I saw that there were countless grievances in the world, and I wouldn't let them go even if I died. I came to the Forgotten River in the underworld, set up a cauldron at the bridgehead of Naihe Bridge, refined Meng Po soup for the ghosts to drink, then forgot my previous love and hate, unloaded my previous baggage, and entered the next reincarnation.

There are different opinions about the origin of Meng Po. According to folklore, Meng Po was familiar with the books of Confucius and Mencius since childhood, and then refined into Buddhism when he grew up. It is said that he has reached the state of "not considering the past, not considering the future". Meng Po often advised the world not to kill when he was on earth. It is said that she lived to be 8 1 year old.

Although Meng Po is old, she has always been a virgin and has never been married. Neighbors call her Grandma Meng Po. It was also at that time that Meng Po developed the true meaning. There is no Meng Po in the underworld. Later, many people began to wonder about their past lives and look for their past relatives. This matter was known by the Emperor of Heaven, who was afraid that the rules of Yin and Yang would be broken because of this recognition.

So Meng Po was ordered to be the god of the underworld, to build a memorial platform (Meng Po Pavilion), and then to synthesize a medicine like wine instead of wine from the dead. This medicine should contain five flavors of life, namely "sweet, bitter, pungent, sour and salty". Drinking this bowl of soup after death can forget all kinds of past events, so there will be no memories of past lives when you are reborn.

It is said that some very uncooperative and cunning ghosts don't drink this bowl of soup. So the Emperor of Heaven specially asked Meng Po to pierce his throat with a copper tube and pour it in.