According to Sima Qian's Records of the Historian, Lao Tzu saw that Zhou had declined, so he resigned and lived in seclusion. When passing through Hanguguan, I was invited by Yin Xizhi to write the classic Tao Te Ching, and I don't know where to go after living in seclusion. Where he lives in seclusion has always been an eternal mystery. Recently, after investigation and demonstration by experts, it was confirmed that the old dwelling cave was Lao Zi's seclusion place, where Lao Zi lived, maintained his health and passed on his classics for a hundred years.

It has been more than 2500 years since Laozi was born. Throughout the ages, the research on Laozi's works can be described as overwhelming. However, the conclusion of the study of Gansu local history is that Lao Zi went out of Hanguguan and continued his westward expedition. His trip in Gansu was generally going out of Hanguguan (now northeast of Lingbao County, Henan Province), passing through Sanguan (now southwest of Baoji City, Shaanxi Province), entering Gansu, passing through Tianshui, Lixian, Qin 'an, Gangu, Longxi, Weiyuan, Lintao, Lanzhou (Gaolan) and Gansu. The publication of this research result has caused widespread controversy in academic circles.