During the Spring and Autumn Period and the Warring States Period, it was equivalent to the post of director of the National Library. The highest position in the Western Han Dynasty was above the prime minister, and even the emperor could not change the history books he wrote. After that, the status was relatively low, and the department was equivalent to today's National Meteorological Administration, including astronomical observation, meteorology, geography and history, all of which were under their control. It was not until the Ming and Qing Dynasties that the task of compiling history books was handed over to the Imperial Academy, and the astronomy department was independent.