The theme song "On Earth" was sung by young singer Jia Lei, composed by Lei Qian and written by Tang Tian. Every lyric is full of tears, accompanied by pictures and lines in the play, which seems to make people feel the joys and sorrows of the Zhou family for decades.
Lei Qian was invited by Jia Lei to compose a theme song of the same name for the TV series "The World on Earth". After watching the demo for 60 minutes, both of them were moved by the ups and downs of the characters and the wave of historical changes. "We cried and finally decided to write a song for the play."