Is Qinyuan Chun Changsha an ancient style poem or a modern style poem?

Neither. "Qinyuanchun Changsha" is a modern poem. New poetry: also known as "modern poetry", as opposed to old-style poetry, generally refers to the new-style poetry produced after the "May 4th" New Literature Movement, including modern metrical poetry, free verse, prose poetry, etc. "Qinyuanchun Changsha" was written between the May 4th New Culture Movement in 1919 and 1949, so it belongs to the category of modern poetry. At the same time, the language of "Qinyuanchun·Changsha" is vernacular, so it is a modern poem.