In History of Ming, the Zheng He biography had explained the life of Zheng He, the motives of the Zheng He's voyages, the passage and harvest of the Western Ocean, but the full text did not explain the meteorology and climate in the Western region. Fortunately, there are Ma Huan's Yingya Shenglan, Gong Zhen's Xiyang fanguo zhi, Fei Xin's Xingcha Shenglan, etc. The three books contain a lot of meteorological and climatic data from Western countries. The author analyzes the division of the global zonal wind zone included in the latitudinal winds of today's meteorology and the division of the average high-pressure zone and low-pressure zone at sea level, which can be used to understand the zone that Zheng He traveled to and from the Western Ocean. It is exactly the zone between the equator and the Tropic of the Subtropics (22.5°N), that is, the equatorial windless zone and the horse latitude windless zone. The wind is weak throughout the year, which increases the difficulty of the crew and sailors paddling with paddles.