Abstract: China is a major producer, consumer, and exporter of garlic in the world. However, in recent years, the frequent fluctuations in the scale of garlic planting have affected the stability and sustainable development of the garlic industry.Scientific analysis of the influencing factors of changes in the garlic planting scale is of great significance for stabilizing the garlic market and promoting the sustainable development of the garlic industry.Using the national garlic planting area from 1989 to 2019 to analyze the characteristics of planting scale changes, the national garlic planting area has been increasing from 1989 to 2006. From 2007 to 2016, the national garlic planting scale has stabilized, and the planting scale has seen zigzag fluctuations from 2017 to 2019. In this paper, the principal component analysis method is used to research and analyze the national garlic planting area and influencing factors data in the past 30 years, and to select the most influential production, unit yield, export value, inventory in main producing areas, garlic wholesale market price, and natural disaster-affected area, the wholesale price of garlic seedlings, the wholesale price of garlic yellow and the planting area of the previous year. The analysis extracts a principal component（contribution rate 80.676%）, which is analyzed and fitted. The main influencing factors of the garlic planting area are the garlic wholesale market price and the area affected by natural disasters. Analysis can provide support for farmers, business decision-making, and government macro-management, which is of great significance for promoting the healthy, stable, and sustainable development of the garlic industry.