The geomantic omen of Longmen Eighth Bureau is also called "Gankun National Treasure", "Eight Diagrams Water Method" and "Positive Ternary Geography", among which "Water Method" is its essence. The geomantic omen of Longmen Eighth Bureau originated in the Tang Dynasty and is said to have been written by Qiu Yanhan, a master of the Tang Dynasty. Qiu Yanhan lived in Xuanzong period of Tang Dynasty and was a famous master of Kanyu at that time. According to legend, his teacher is a crane fairy. Because he ordered the emperor's dragon cave among the people, the sky was abnormal and the company saw him angry with the emperor. After the incident, he was placed under house arrest by the court. Xuanzong ordered him to write books such as "The Secret Book" and "The Jade Letter Classic", and sent Yang Junsong to take special care of them. Yang Gong was fascinated by his geomantic secrets. After the Huang Chao Uprising, Chang 'an was captured and Nuozong fled to Sichuan. Yang Gong took the opportunity to steal the secret book of Jade Letter and hid it among the people. However, because of its simple application and high efficacy, it conforms to the Heluo theory, so it has always been regarded as an orthodox geomantic tactic, which has been passed down to this day. "Longmen Eighth Bureau" feng shui pays special attention to the water method, which should be very special for all kinds of good and bad luck brought by different directions.