Yutong, on a conceptual basis they mean similar things: that is, to get rid of.
Their use depends on the context:
1) Delete - is used more often with computers and technology. I deleted the document from my USB. Can you delete that photo? He deleted me off Facebook.
2) Remove - is used in a broader sense. I removed the document from my USB (is fine, but delete is used more commonly).
However, there are some situations when you should use remove, and not delete. In particular, when you are physically getting rid of something from a location, you cannot use delete. For example:
- I removed myself from the awkward situation. You can't say I deleted myself from the awkward situation, because no technology was involved.
- I removed the laptop off the table. You can't use delete there, because the act of getting rid of is physical, not virtual (on technology).