In recent two years, the profit low point of PVC production enterprises by ethylene method increased slightly, but the high point decreased slightly, which was in line with the trend of PVC price operation in recent two years. The profit peak of PVC production enterprises by calcium carbide method is also declining, but the low point is basically stable, and it has been maintained at 200-250 yuan/ton. Even if it falls below 200 yuan/ton, profits will rebound quickly, and futures will follow a wave of rise. From this point of view, the profits of PVC production enterprises by calcium carbide method can be used as an important reference to judge the long-term market of PVC. Profits are of great significance to enterprises. First, profit is the core index reflecting the business performance of enterprises. Second, profit is the basis for enterprise stakeholders to distribute benefits; Third, profit is the basic source of sustainable development of enterprises. Under normal circumstances, when profits decline, production enterprises will reduce the supply of goods in order to seek a rebalancing of supply and demand and make profits rebound. When profits rise, there are two situations. One is that when manufacturers have pricing power, or when the supply of goods is in short supply, profits will rise, and manufacturers will increase supply to expand corporate profits; The other is that commodities are in a pattern of oversupply. Once profits rise, end consumers will have more choices. At this time, if the supply is rashly increased, the goods produced by enterprises often cannot be sold, resulting in a backlog of inventory, which makes enterprises sell at a reduced price, thus achieving the purpose of reducing inventory.