Adjust the camera view actually separate all my objects I would like to adjust the camera view, so I press the CtrkAlt0 to switch to the camera view window, then I try to adjust the camera window.



Then, I press the G key, and try to move the view window up or down, but finally, I see that all the objects were moved, not the camera view itself:



What causes this behavior?

BTW: I have just tried a very simple blender file (which only contains the default Cube, and I can correctly move the camera view), so are there some settings wrong in my first case? Thanks.

Edit: test blend file
You had "proportional editing object mode" enabled. Toggle it off and it should work as expected.