Composite knocking-over bar

The utility model discloses a combined type knocking-over bar which comprises a metal insert and a base with a low thermal expansion coefficient, the top of the base is downwards provided with an insert groove along the length direction of the base, the insert is inserted into the insert groove, the insert is connected with the base through a fastener, and the insert is connected with the base through the fastener. The top of the insert extends out of the top of the base, a plurality of tooth grooves are formed in the top of the side face, facing the outer side, of the insert at intervals, a plurality of unloading grooves are longitudinally formed in the positions, below the tooth grooves, of the insert at intervals in the length direction of the base, and the unloading grooves downwards penetrate through the insert to form a notch in the bottom of the insert. The unloading groove reduces uneven deformation of the whole insert caused by thermal expansion and cold contraction, the base with the low thermal exp