improve on/upon something
phrasal verb with improve verb [ I or T ] uk/ɪmˈpruːv/ us/ɪmˈpruːv/
改进，提高
to do something in a better way or with better results than before
Last time she ran the race in 20 minutes, so she's hoping to improve on that. 上次比赛她跑了20分钟，因此她希望在此基础上再作提高。