The invention provides an edge turning device with a sawtooth-shaped pressing block. The edge turning device is used for turning a corner-part rim material, which is located at a corner part of a skylight opening part, and an edge-part rim material, which is located at an edge part of the skylight opening part, of a decoration fabric material which is adhered to the inner surface of the skylight opening part of an automobile interior decoration roof from the inner surface of the skylight opening part to the outer surface of the skylight opening part. According to the technical scheme, at leastone of four edges of the skylight frame opening part is the left-bracket-shaped edge, the edge turning device comprises a frame mechanism which corresponds to the skylight opening part in size, a horizontal pushing mechanism which is arranged on the outer side of the left-bracket-shaped edge, and a control mechanism for controlling the frame mechanism and the horizontal pushing mechanism to act.The edge turning device can be used for carrying out material edge turning at the left-bracket-shaped edge of the skylight opening part, and wrinkling is not prone to occurrence during material edge turning. The invention provides a hemming device having the edge turning device with the sawtooth-shaped pressing block. The invention provides a hemming method for the left-bracket-shaped edge, and the hemming method is used for hemming of the left-bracket-shaped edge of the skylight opening part of the automobile interior decoration roof.