I have tried update the linux kernel, and acted upgrade,but these don't work. I have also borrowed a GTX 980 from my parterner. Ubuntu recognize the GTX 980.And then it worked very well. So I think I should intall the correct driver for the i9 9700k. But I failed . Could you tell me how to intall the correct driver and make the system rocognize intel uhd graphics 630.
This definitely sounds like you need newer drivers. Have you asked about this on the various Linux and Ubuntu forums? Most of Intel's support for Linux is provided on/through Intel's Open Source site, 01.org. There are sub-pages and forums specifically for graphics (start here: https://01.org/linuxgraphics).
Hope this helps,