With the economic development in China and the promotion of the conversion of “coal to gas” policy, natural gas, as a clean energy, will be increasingly applied to the future life of residents. Natural gas storage tank is an important part of natural gas supply gas source system, and the tank safety has received much attention. As a common geological disaster, foundation settlement is likely to cause the gas tank to tilt, which may even cause gas storage tanks to deflate and explode. Therefore, it is particularly important to carry out settlement observations at natural gas storage stations. As a common means of settlement monitoring, seo-robot has the advantages of high precision, low cost and easy operation. In the measurement, due to the observation conditions and some other factors, the measurement data is inevitably superimposed on the “noise” interference, in order to eliminate the abnormal data, Grubbs criterion is used for data processing. Taking No. 1 gas storage tank of Nanchong gas storage and distribution station as an example, this paper introduces the observation technology and data analysis of the gas storage tank settlement.