With the growth of demand for sewage treatment and the development of chemical, metallurgical and other industries, the market demand for offshore fans in China continues to rise. In the past five years, the output of wind turbines in China has also increased, from 3700 in 2017 to 11000 in 2021. With the increase of the output of Li Fan, its output value also increased, from 3700 units in 2017 to 11000 units. With the increase of the output of centrifugal blower, its output value also increased, from 1.2 billion yuan in 2017 to 4.6 billion yuan in 2021.Fan is a kind of machinery mainly used for pumping, conveying and improving fluid energy. It is mainly used in ventilation of mines, underground projects, underground power plants, boiler ventilation and air induction; Emission of high temperature corrosive gases from chemical plants; Workshop air conditioning and ventilation of atomic protection equipment. Fans are widely used. In short, they are mainly used to assist full combustion, ventilation and transportation, and almost involve all fields of the national economy