The invention provides a negative-angle bending hardware stamping device. The device comprises a lower die plate, wherein a hardware body is placed on the lower die plate; the lower die plate moves upwards under the driving of a driving component; a swing block is hinged to the lower die plate; a first guide surface and a second guide surface are arranged at the top of the swing block; the swing block moves towards the hardware body under the driving of the driving component; the first guide surface abuts against the bending end of the hardware body; a slotting cutter is fixedly arranged on the upper die plate; a third guide surface is arranged at the end part of the slotting cutter; the position of the third guide surface corresponds to the position of the second guide surface; the swingblock rotates clockwise under the pushing of the third guide surface; a punching sliding block is slidably arranged in the middle of the upper die plate; and the punching sliding block moves towards the bending end under the pushing of the lower die plate until the punching sliding block abuts against the bending end. Compared with the prior art, the number of dies required by negative-angle bending of hardware is reduced, the effect of one-time stamping forming is achieved, and the stamping efficiency of negative-angle bending of the hardware is improved.