The spatial distribution of underground coal seams presents various changes, which are distinguished from their spatial geometry and material properties, and coal mining opportunities meet different coal seam cutting function requirements.

       (1) Thick and thin coal seam cutting. Coal seam thickness is divided into 6 grades, that is, extremely thin coal seam with a thickness of less than 0.8 m, thin coal seam with a thickness of 0.8-1.3 m, medium-thick coal seam with a thickness of 1.3-3.5 m, thick coal seam with a thickness of 3.5-5 m, and a thick coal seam with a thickness of 5-8 m. m ultra-thick coal seam and ultra-thick coal seam thickness greater than 8 m, the thickness of the coal seam puts forward functional requirements for the mineable height of the shearer, which is the most important functional characteristic of the shearer.

       (2) Inclined coal seam cutting. The inclination of coal seams is divided into four levels, that is, near-horizontal coal seams with an inclination angle of less than 8°, gently inclined coal seams with an inclination angle of 8° to 25°, moderately inclined coal seams with an inclination angle of 25° to 45°, and steeply inclined coal seams with an inclination angle greater than 45°. The coal shearer working in the coal seam with an inclination angle greater than 35° is called a large inclination angle coal shearer. It is required to have large traction force, strong climbing ability, reliable anti-skid brake device, and a backup anti-skid hydraulic winch.

       (3) Long and short coal seam cutting. According to the coal seam occurrence conditions, it is divided into long-wall mining with a working face length greater than 50 m, and short-wall mining with a working face length less than 50 m. Shearers generally use rail traction and side cutting, while short-wall shearers generally use crawler walking and front cutting.

       (4) Cutting of soft and hard coal seams. Coal seams are divided into five grades according to the hardness f, that is, extremely hard coal seams with f ranging from 4.0 to 5.0, hard coal seams with f ranging from 3.0 to 4.0, medium hard coal seams with f ranging from 1.5 to 3.0, soft coal seams with f ranging from 0.8 to 1.5 and f 0.5 to 0.8 very soft coal seam, the shearer for cutting coal seams with f greater than 3 should meet the functional requirements of high power cutting part and hard pick.

       (5) Cutting of undulating coal seam. Affected by geological structural factors, the coal seam is bent and deformed to cause thickness changes. Therefore, the coal shearer is required to have the functions of adjustable height rocker arm and automatic height adjustment and cutting, so as to realize the profiling cutting of the coal seam.