Here is the issue, when I add a stamp copy onto a grid and use mountain to create shape, there are always some lines going straight forword up with no mountain effects, even fit01 range changed, there are still some. But this is not happend with a copy to point. Is there any trick in stamp copy ?

You should probably use something like Point Jitter instead of Mountain for modifying points on a line since the Mountain node requires well-formed normals (implicit or explicit) to work properly. If you drop a Point Wrangle after the Copy to Points or Copy Stamp node and write “@N = @N”, you'll see that some of the points are given normals that are {0,0,0}. These are points that won't be affected by the Mountain node and will remain perfectly vertical. Interestingly the Copy Stamp node is more likely to produce points with invalid normals, but that is probably some undefined behavior.

Attribute noise can work as well. Mountain only moves along the normal, so even if the normal is well defined, the points will all move in the same direction.