First of all, it is recorded in history that the Sui and Tang Grand Canal is about 2,700 kilometers long. At present, the length of the Beijing-Hangzhou Grand Canal is over 1790 kilometers, and there is still a certain gap in length. At that time, the Grand Canal was still longer than the present Beijing-Hangzhou Grand Canal. In addition, the reason why the Sui and Tang Dynasties Grand Canal is longer than the Beijing-Hangzhou Grand Canal is partly due to Yang Di's political rule. Due to the previous division, the Sui Dynasty was roughly divided into three parts: Guanlong, Hebei, Shandong and Jiangnan, but Yang Di wanted them to remain as a whole, which became the main reason for Yang Di to build the Grand Canal. The Grand Canal in Sui and Tang Dynasties was definitely connected with Guanzhong area.
Later, after the demise of the Tang Dynasty, the economic and political center of China moved eastward, and the original German Ministry became the present South and North. Therefore, the current Beijing-Hangzhou Grand Canal mainly hopes to communicate with the north and the south, and without the Grand Canal, it will not communicate with the west. Then the Sui and Tang Dynasties Grand Canal was divided into three parts, so the central city should be in Luoyang, Henan. The purpose of the Beijing-Hangzhou Grand Canal we are talking about now is to connect the north and the south, but the city center of China has changed and become the present capital, that is, Beijing, so the central city of the Beijing-Hangzhou Grand Canal is naturally Beijing.
The above is the difference between the Sui and Tang Grand Canal and the Beijing-Hangzhou Grand Canal, which is mainly manifested in three aspects. First, the length of the two is slightly different, and the Sui and Tang Dynasties are longer. The second point is that the division of the two regions is different. The Sui and Tang Grand Canal consists of three parts, while the Beijing-Hangzhou Grand Canal has only two parts. Third, their central cities are different.