Abstract: The ionospheric delay is an important error source that cannot be ignored in satellite navigation and positioning. The global ionospheric TEC grid (GIM) data is very convenient to users because it provides TEC values at regular grid points globally. Based on the advantages of simplicity, high efficiency and easy maintenance of Linux Shell, this paper uses Linux Shell script to extract and analyze the ionospheric TEC grid data, including global and optional area ionospheric TEC data extraction, mean calculation, latitude and longitude grid difference calculation, and maximum and minimum value extraction. Therefore, some references could be provided for the analysis and research of annual, seasonal, weekly and daily variation characteristics, and some other temporal and spatial variation characteristics of global or regional ionospheric TEC based on GIM data.