I found that the original method didn't work anymore, so I added the latest method, and directly searched for Mr. Song Kechen on Baidu. The first one was the teacher's homepage, where there are data sets to download.
http://faculty.neu.edu.cn/songkechen/zh_CN/zhym/263269/list/index.htm
Recently, I learned that I wanted Dongda’s hot-rolled strip surface defect data set, but the address of the official website was always inaccessible. Finally, I found a link to visit the old page, and I understood the reason. The web page was updated, the server was changed, and the DNS domain name resolution all pointed to the IP of the new official website server. Therefore, the address of the old IP cannot be accessed. The solution is not to use the domain name, but to directly use the IP address to access.
http://202.118.1.237/me/songkc/Vision-based_SIS_Steel.html
Note that the hyperlink also uses a domain name, so click on the hyperlink if you want to download something, and change the domain name of the browser's access address to IP
http://202.118.1.237
For example, the steel data I need:
http://202.118.1.237/yunhyan/NEU_surface_defect_database.html