Shear knife provided with self-lubricating device

The invention discloses a shear knife provided with a self-lubricating device and belongs to the technical field of metal cutting. The shear knife is composed of a shear knife body, the self-lubricating device, an active carbon fiber ribbon and a spring set, wherein the active carbon fiber ribbon is fixedly connected onto the self-lubricating device; and the shear knife body is connected with theself-lubricating device through the spring set. In the original state, a spring at the top end of the self-lubricating device is compressed; the bottom end is pressed on to-be-cut metal; the side faceof the bottom is in tight contact with a rear knife face; the shear knife body moves downwards; the bottom face of the self-lubricating device gives certain pressure to the to-be-cut metal through the compression action the spring; then, the to-be-cut metal is pushed to move towards the direction of the shear knife body; the upper surface of the to-be-cut metal has friction with the self-lubricating device to bring out a