It was widely said in the early days that Zheng He went to the Western Seas to find the trace of Wen Jian. His name is Zhu Yunwen, also known as Hui Di, and he is the grandson of Zhu Yuanzhang, the Ming Emperor. At the beginning of his reign, Wen Jian was determined to cut off the vassals. 1June 399, Judy, the prince of Yan, became the teacher of Jingnan in the name of "the frontier of the Qing army" and openly rebelled against Wen Jian. 1402, Judy led the army to capture Nanjing. When Nanjing fell, "there was a fire in the palace, and the emperor (Wen Jian) didn't know what to do." Some people say that "Emperor Wen Jian became a monk". The Biography of Zheng He in the Ming Dynasty bluntly said: "Cheng Zu suspected that Hui Di died overseas and wanted to trace it." Later, many people agreed with him. Xu Liqun wrote in the section "The Historical Story of China: Three Treasures Eunuchs' Sailing to the Western Seas": "The purpose of Yongle's sending Zheng He to the Western Seas is to find the Emperor Wen Jian. Because after Emperor Yongle usurped the throne of Wen Jian, Wen Jian disappeared. Yongle was afraid that he would flee abroad and come back for restoration in the future, so he sent someone to look for him. "Others, such as Fan Wenlan's A Brief History of China and Wu Han's Foreign Policy, and Zheng He's voyages to the West in the early Ming Dynasty, also believe that Zheng He's voyages to the West were accompanied by the emperor's secret mission, that is, to find the whereabouts of the emperor.
Some scholars think that Zheng He's voyage to the West to find Wen Jian is far-fetched. Emperor Wen Jian was loyal and defeated by the weak, and was ousted from the throne by Judy. Even if he fled abroad, what ability would he have? Judy should also understand these situations, so he won't send someone to search for the whereabouts of Zhu Yunwen again and again. In addition, whether Wen Jian escaped from Nanking is also a controversial issue. There are many indications that Emperor Wen Jian died in a fire before the fall of Nanking. With his death, it is even more impossible to find him. Some people think that Zheng He's voyage to the Western Seas is to "show off his strength" and "educate foreigners" and make overseas countries "take China as their guests". At the same time, he is also responsible for communicating the economic and trade exchanges between China and overseas countries.
In recent years, the angle of exploring the reasons for Zheng He's voyage to the West has changed. Some scholars believe that Zheng He's mission to the Western Seas varies with time. Zheng He's first task is to appease the neighboring small countries and reduce foreign intrusion into China. Later, it was mainly for trade, advancing into the unknown world and opening up new waterways.
Some people think that Zheng He's voyages to the West have political purposes. Zhu holds this view in the article "An Analysis of Zheng He's Purpose of Going to the West" (Zheng He's Essays on Going to the West). First, he denied the theory of "showing off force in foreign countries". He said that Zheng He used force to subdue the foreign king twice overseas because he had to fight back in self-defense. The foreign policy pursued by Zheng He is based on "Huairou" and based on friendship and peace. It is blind to say that Zheng He's voyage to the West is an economic factor. Looking at the relevant documents of the Ming Dynasty, I have never seen Zheng He stationed troops in foreign countries and plundered the economy. Zheng He sent many foreign businessmen back to China to do business, and Emperor Yongle ordered no taxation. He said, "Today, foreigners come from afar, infringe on their interests, gain a lot, but also suffer a lot of humiliation."
Zhu believes that Zheng He's voyage to the Western Ocean opened a closed and rigid diplomatic door. The Ming dynasty was just established, and small neighboring countries often came to pay tribute. Tribute at that time was essentially a kind of property exchange. Tribute was given by the Ming Dynasty, and gifts were often greater than tributes. At the beginning of the Ming Dynasty, Ming Taizu ordered that tribute be restricted from one to three years old, and some countries, such as Japan, restricted it to ten years, so the relationship between the Ming Dynasty and overseas countries was almost cut off, and the economy and trade almost stopped. As a result, smuggling activities were rampant, armed smuggling became the norm, and the momentum of the Ming Dynasty gradually declined. Emperor Yongle decided to change this political situation after he came to power. Every time Zheng He was sent to the Western Seas, his first task was to award "Zheng Shuo" to restore and develop the diplomatic relations between the Ming government and overseas countries. Zheng He's first voyage to the West brought a group of pirates who had been plundered by Chen Zuyi for a long time in Sanfo Qi to justice, which cleared the way for communication with sea lanes and improved the reputation of Yongle government.
The result of the successful foreign policy of Emperor Taizong of Ming Dynasty was that "Emperor Taizong was everywhere, aiding foreigners, traveling by boat, knowing human resources, bringing silks to Korea, sailing by ladder and paying tribute". However, the social and economic cost caused by this foreign policy in the early Ming Dynasty was "not negligible", so Zheng He's voyage to the West was strongly opposed after the death of Emperor Taizong of Ming Dynasty.
Scholars are keen on studying Zheng He's voyages to the West. Unfortunately, this problem was not solved at the first seminar on Zheng He's research in 1983 and the seminar on the 580th anniversary of Zheng He's voyage to the West in 1985.