The invention relates to a protecting net. A steel beam is fixedly arranged at the surface of a roof, a plurality of side protecting nets, a center protecting net and two oil cylinder protecting nets are respectively hung at the lower surface of the steel beam, the center protecting net consisting of four center protecting sheets is positioned in a mixing kettle area, a rotary plate leaning plate of each center protecting sheet is tightly attached to the outer circumferential surface of a blade rotary body, the oil cylinder protecting cylinders respectively consist of two oil cylinder protecting sheets, an oil cylinder leaning plate of each oil cylinder protecting plate is tightly attached to the outer circumferential surface of an oil cylinder guide column, and the side protecting nets are respectively arranged at the two sides of the center protecting net according to the protecting requirement. The protecting net has the advantages that in the combination process, the protecting nets are fixedly connected by cloth bags through connecting holes; the possibility of excessive matters entering the mixing kettle above the protecting net is thoroughly prohibited, and the safety hidden hazards are avoided; by adopting the modularized protecting net, the excessive matters can be controlled, and the protecting net is conveniently detached for cleaning and maintenance.