My kid just learn using computer not for a long time. And one week ago he made all the pics on my computer gone and I have no idea how he did this. I found the trash bin on my Mac and didn?

There several possibilities. How he did it may be important if you didn't back up.

1. He moved them. Search for images and find them. Put them back.

2. He deleted them. Open Time Machine, go to the place where you keep your photos. Go back in time until they appear. Press restore.

If you don't back up... get a data recover program such as Disk First Aid, and use that to recover them. By far the easiest way is to back your stuff up and use Time Machine to recover lost files.