1. Search internationally renowned remote sensing data providers, such as NASA and USGS, to find the hyperspectral image data set provided by them. These data are usually obtained by registering an account and downloading the corresponding software, but they are all free.

2. Visit some open data platforms, such as Google Earth Engine, which provides a lot of remote sensing data, including hyperspectral image data, and search and download the required hyperspectral image data on this platform. It should be noted that some data need to create an account and accept the use agreement.

3. Search relevant academic research institutions and projects to see if they provide free hyperspectral image data. These data are usually the results of specific research projects, so it is necessary to quote and abide by the corresponding usage regulations.

4. Download from professional websites, such as Geospatial Data Cloud Platform, computer network information center, etc. These platforms provide a large number of remote sensing images and geographic information science data, which can be downloaded and used for free. However, these data often need to be processed and analyzed by software or online tools.

In a word, obtaining free hyperspectral images requires multi-channel searching and downloading, and at the same time, we need to pay attention to the accuracy and availability of data and abide by the corresponding usage regulations.