According to the degree of refining, oils and fats are generally divided into four grades: secondary oil, primary oil, advanced edible oil and salad oil. Salad oil itself is the highest grade, there is no grade.

Salad oil is a high-grade edible vegetable oil refined by degumming, decoloring and deodorizing (degreasing). Mainly used as raw oil and seasoning for cold salad or sauce. Salad oil sold in the market mainly includes soybean salad oil, rapeseed salad oil, rice bran salad oil, cottonseed salad oil, sunflower salad oil and peanut salad oil.