First, it has something to do with Zhu Yuanzhang's unification by Zoroastrianism.
Before Zhu Yuanzhang followed Tanghe to take refuge in Guo Zixing, many forces chanted anti-Yuan, but many of them were suppressed. At that time, Han Shantong, the "Ming King" in the north, was the leader of the White Lotus Sect, followed by the Red Scarf Army led by Guo Zixing after Zhu Yuanzhang's secularization. But Han's good times didn't last long, because he was quickly captured and beheaded by Yuan people, so the title of rebel leader fell on him.
In fact, both the Red Scarf Army and the White Lotus Sect of Han believed in Zoroastrianism, so Zhu Yuanzhang finally became the leader of the rebel army, that is, when he became the leader of Zoroastrianism. Zhu Yuanzhang named his country name "Ming" after he ascended the throne because he was obsessed with digging wells, and he knew that his accession to the throne was the result of Zoroastrianism.
Second, in order to stabilize the hearts of those old employees.
As I said just now, both the Red Scarf Army and the White Lotus Sect believe in Zoroastrianism, so the rebel army is actually composed of Zoroastrianism. Moreover, after Zhu Yuanzhang ascended the throne, he also used many colleagues who had fought together before. In other words, there are still many Zoroastrianism in the army and even in the DPRK. Zhu Yuanzhang set the year number as "Ming", probably to stabilize them!
Third, in order to show the rapid development, the Central Plains changed dynasties.
Ming characters are actually composed of a word "day" and a word "month", and the combination of words is changing with each passing day. Zhu Yuanzhang may also want to say that the days of the Yuan Dynasty's rule have passed, and now he is in office, so he will use the title of "Ming"!
Later, the Qing army entered the customs, and Zoroastrianism was revived in the form of Bailian Sect under the banner of "anti-Qing and regaining sight". Therefore, the biggest possibility that Zhu Yuanzhang changed the name of the country to "Ming" is that Zoroastrianism once opposed the Yuan Dynasty and participated in the process of realizing the reunification of the Ming Dynasty.