Only the top of my cylinder can move with bone.

Support Modeling
1

Hello.guys.
I have a problem, hope you can help me.
Only the top of the cylinder will move when I rotate the bone in the pose mode.

As the picture,I’m sure the cylinder is in the envolope.
I’m also sure the cylinder is attched with armature modifier.

2

The bones move vertices. The only vertices I can see are the ones at the end which are moving. You need to add more geometry if you want other parts to also move. Ctrl+R adds edge loops

3

Oh! Thank you! You sove my problem! Thank you a lot!!