First of all, I thought it was a problem with the path. After various attempts, I found that my path was okay, and using the browser address bar to directly access this picture was also the picture before it was displayed.
Later, I gave the new picture a name and went to visit this picture and found that I was able to access it. Originally, I used the same name for the two pictures.
After a bit of tricks, I cleared the browser's image cache and finally solved it, which is the browser cache problem.
