Compared with the manufacturing of the traditional infrared material, such as signal crystal germanium, zinc sulfide, zinc selenide etc, chalcogenide infrared glass is suit for precision molding for the low soften temperature to have large mass industry production. And the mold designing is one of the key technologies of precision glass molding. It takes the way of simulation method to design the mold. The mold processing of a sample chalcogenide glass from the technical drawing, mold design, molding to the lens are introduced. From the result of the precision molding, the technology of finite element simulation is a useful way to guiding the mold design. The molded lens by using mold process fit the design requirement.