The present disclosure relates to a display back plate and a display device. The display back plate includes a display area and a non-display area surrounding the display area, wherein the non-display area is provided with at least one circle of first cofferdam surrounding the display area, a first thin film encapsulation layer is arranged on the first cofferdam, and the non-display area is provided with a fan-out area, a second cofferdam is arranged on one side of the first cofferdam close to the fan-out area, the second cofferdam is provided with a first bonding pattern including a plurality of protrusions, and the first thin film encapsulation layer at least partially covers the protrusions.