How to use F5 Bigip(v11.4) to detect pool member's CPU and Disk utilization?

You've a few options. If these are HTTP boxes you could perhaps run a script creates a HTML page containing the CPU figure and use a HTTP monitor to 'read' it.

 

Perhaps the SNMP monitors might be useful too.

 

You could also use an external monitor to call a script that queries the CPU somehow.

 

I'd suggest you take a look at the Monitors Reference here: http://support.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/ltm-monitors-reference-11-6-0.html