The ambition of Kun Peng is not an idiom, but a combination of words with certain allusions. According to legend, in ancient times, there was a big bird named Kun Peng, with nine Wan Li on his back, and his wish was to fly for nine days. Quoting this allusion means that a person has very high aspirations and pursuits (reaching the height of heaven).

The story is legendary, and the phrase "Kun Peng's ambition" implies the pursuit of lofty goals and indomitable spirit, which is a very lofty perseverance.