Improve the speed in China

If I want to improve the speed in China with Business plan, do I need ICP?

Yes, however you would still need to pay for access to CF’s China datacenters by talking to the Enterprise sales team. You can ask for the Enterprise plan with only the china network which will cost less than if you were asking for every other feature as well.

Contact sales via this page: https://www.cloudflare.com/network/china/