According to the description of the northern Wei folk song "Mulan Ci" by scholars in the Sui and Tang Dynasties after the northern Wei moved its capital to Luoyang, there are two main opinions about the historical age of Mulan. First, during the Taizu period of the Northern Wei Dynasty, Mulan joined the army as her father and took part in the Northern Wei Dynasty's battle against Rouran. Mulan participated in the Northern Wei Dynasty's battle of attacking the desert and cutting Rouran for many times, and her performance was outstanding. No one found out that she was a woman. The second statement is: During the reign of Emperor Yining of Sui Dynasty, Turks invaded the frontier, Mulan disguised herself as a man, joined the army on behalf of her father, and fought in the battlefield for many years, making many meritorious deeds. Mulan Ci is a popular folk song in the Northern Dynasty, which lacks close relationship with the Sui Dynasty. This statement at the end of Sui Dynasty was in conflict with the full text in many places, but somehow it spread. ) In the Tang Dynasty, Mulan was posthumously named "General Filial Piety" and was commemorated in a shrine. Hua Mulan's deeds have been handed down to this day, mainly due to the swan song of the northern folk song Mulan Ci. This is a long narrative poem compiled by Guo Maoqian in Song Dynasty, praising the legendary story of Mulan disguised as a man and joined the army as her father.