Flaxseed is a traditional oil crop in China, but it is unknown in the deep mountains and people know its value. Flax is divided into oil flax, oil fiber flax, and fiber flax. Flax produced in the three northeastern provinces is used for textile purposes, such as the common linen mats or linen clothing. Oil flax is mainly produced in central and western Inner Mongolia, northern Shanxi, and Huining, Gansu. The flax oil here is also known as sesame oil locally, mainly because it was introduced to China by Zhang Qian, an envoy of the Han Dynasty in ancient times. Traditional Chinese medicine research shows that flaxseeds produced in the high-altitude areas of Huiteng and Schiller in Inner Mongolia are better. Flax is mainly distributed in temperate regions, and the oil content of flaxseed is generally 40-60%. Unlike other edible oils, the main fatty acid in flaxseed oil is linolenic acid, with a content of about 50%. The temperature in areas where flax grows has a significant impact on the fatty acid composition of flax seeds. Flaxseed oil in cold regions generally has a higher degree of unsaturation, while flax oil produced in warm regions has a lower degree of unsaturation. Flaxseed oil contains abundant alpha linolenic acid, which is a good way to supplement linolenic acid.