Abstract: As one of the three major cereals, wheat is widely planted all over the world. About 1/3 of the world's population uses wheat as the main food, so wheat is called the "world food". Wheat is also the staple food of about half of our country's population, which plays an extremely important role in our country's grain composition. The level of wheat production and consumption in my countries ranks first in the world. About 90% of wheat is processed into wheat flour, which is used as a basic raw material for the production of steamed bread, noodles, cakes, and other pasta products. In recent years, as people's consumption concept has changed to a"green, healthy and sustainable" development, the milling industry has also abandoned the past one-sided pursuit of "fine and white" over-processing concepts and proposed "moderate processing" new concept. In the past, "fineness", refers to the particle size of wheat flour, is one of the most important indicators for evaluating the quality of wheat flour. However, fineness inevitably increases the difficulty of grinding as well as the energy consumption, which does not conform to the new concept of "appropriate processing" in the milling industry. Four kinds of endosperm granules of 1M₁, 1M₂, 1M₃, and 2M₁ were used as the raw materials, and the roll distance was adjusted online to obtain wheat flour with different grinding strengths. The effect of the grinding strength on the size distribution, basic indexes of wheat flour, gelatinization characteristics and dough rheological characteristics of different systems of wheat flour was studied. This study provides theoretical support for proper grinding in flour mills. The results showed that the average particle size, moisture content, and falling value of wheat flour in each system decreased with the increase of the grinding strength. Whiteness and damaged starch content increased with the increase of grinding strength. The starch content changed irregularly with the increase of the grinding strength, and the ash content was far below the national standard first-class product requirements. In the gelatinization characteristics, the peak viscosity and setback value decreased with the increase of grinding strength in different systems. The wheat flour with stronger grinding strength of each system had lower breakdown value. The gelatinization temperature of 1M₂ and 1M₃ system flour decreased with the increase of grinding strength. In the rheological properties, the water absorption of wheat flour in different systems increased with the increase of the grinding strength. 1M₂ and 1M₃ wheat flour had long formation time and stabilization time, low weakening degree and high farinograph index. While, 2M₁ wheat flour showed the opposite properties. The extension ratio of wheat flour in the four systems of 1M₁, 1M₂, 1M₃, and 2M₁ increased with the extension of fermentation time, and increased with the increase of grinding strength.