At present, there are three types of small rice mills popular in China's market: separated rice mills, husked rice mills and pneumatic rice mills. The separated rice mill was developed in the early 1970s. Structurally, it includes four parts: ① The feeding part consists of a hopper, a hopper seat and a feeding adjusting plate. ② Rice milling part: It consists of machine cover, machine case, spindle, roller, rice knife, rice screen, pressure door, etc. ③ Rice bran separation part: It consists of fan, air duct, separator, vacuum cleaner, etc. ④ Machine foot part: It consists of left and right machine feet, tension bolts, chaff skateboards, etc. Products range from 6NF-5.8 to 6NF-9 (the number after the horizontal line is the diameter of the rice roller in centimeters). The hourly output is generally about 50 kg to 1200 kg, and the price is about 1600 yuan from 400 yuan. It is characterized by simple structure, convenient installation and operation, and low price, but the model is aging, the rice quality accuracy is poor, the rice bran separation is not clean, and there are many broken rice, which is gradually in the trend of elimination. This model is suitable for areas with low requirements for rice quality, remote or underdeveloped economy. The rice husking and milling machine is a product of the 1980s. Compared with the separated rice mill, its structure is equipped with a set of rubber roller hulling device, and the process of hulling first and then grinding white is adopted, which reduces the pressure in the rice mill room, so the processed rice is of good quality and the rice bran is separated cleanly. This model mainly includes NZJ- 10/8.5 (10 refers to matching power, and 8.5 refers to the diameter of rice roller). The output per hour is generally from 800kg/ hour to 1200kg/ hour, and the price per unit is about 5,000 yuan. Due to complex structure, high price, few manufacturers and low market sales; The pneumatic rice mill is a product in the mid-1980s. This type of rice mill is divided into single air duct and double air duct. Among them, the single air flow rice mill mainly processes brown rice, or adopts the process of grinding the shell lightly first and then grinding white. The double air duct rice mill can complete rice hulling and rice milling at one time. The output of this series of products ranges from 200 kg to 3000 kg per hour, and the price ranges from 1800 yuan to 5000 yuan. The machine is improved on the basis of the separated rice mill, and adopts axial ventilation, which is not only beneficial to rice hulling and rice milling in the rice mill room, but also can effectively remove the hull components in rice. The processed rice is white and bright, and the rice temperature is low, which is beneficial to the storage of rice. Due to the above advantages and good cost performance, it has gradually become the mainstream variety in the market in recent years.