can I get from the Kunming airport to the Crowne Plaza hotel by subway?

Subway cannot take you there directly. Anyway, here is the way: take line 6 to East Bus Station. Then transfer to bus no. K9 and get off at Weiyuan Road. After that, walk to your hotel.

Or take shuttle bus line 6 to Dongfeng Square and then the distance to your destination is around 900yd. It is easy to walk there.