The incoming coal from thermal power plants is mostly sampled from the coal flow of the coal conveyor belt. When manually sampling on the coal conveyor belt, the shovel mouth should be tightly attached to the belt and taken at once, without leaving any bottom coal. If sampling is divided into two parts, sampling should be rotated on both sides of the belt, and the two should be merged into one sub sample. Manual sampling is only limited to conditions where the belt speed does not exceed 1.5m/s, the coal seam thickness on the belt is not more than 0.3m, and the coal conveying volume is not more than 200T/h.