what is the easiest public transport to CCTV, Beijing? By subway or bus?

You must refer to Nobotel Xinqiao, right? And would you go to the CCTV new location at West Third Ring Middle Road? If so, both bus and MTR can be ok.
By bus: walk from your hotel to Beijing Station Qianjie Station to take bus no. 9 or 729 to Hujialou East Station, which is within walking distance from your destination.

By MTR: walk to Dongdan Station to take line 1 to Guomao, where transfer to line 10 to get off at Jintaixizhao Station. Get out from exit 9 and walk there within around 700m.