A method for verifying tolerance of a connector molding die includes, firstly, providing a first connector molding die, and molding a first optical connector using the first connector molding die. The centers of the lenses relative to the center of the first transmission surface are located. A second connector molding die is provided. A second optical connector is molded by the second connector molding die. The central locations of the first blind holes are determined by measuring the central locations of the second blind holes based on the center of the second transmission surface. Difference values between the locations of the centers of the lenses and the central locations of the first blind holes are determined.