A fabrication method for a diary or electronic device cover, the fabrication method includes the steps of: disposing an elastic first synthetic resin on a joint panel; disposing a second synthetic resin on the first synthetic resin; disposing a third synthetic resin different from the first synthetic resin and the second synthetic resin in material; joining the first synthetic resin, the second synthetic resin, and the third synthetic resin at a plurality of points; and injecting air into a space between the first synthetic resin and the second synthetic resin to allow the cover to have a bulged surface.