Focusing mechanism is an important part of zoom lens in production manufacturing engineering, in order to meet the reading and detection of anti-counterfeiting label laser anti-counterfeit platform, this paper presents the principle and method of using linear driving mode focusing and introduces the focusing mechanism which consists of a stepping motor, linear guide rail, rail screw or gear rack, the DSP controller. By contrast test, it verifies the location precision ball screw type focusing mechanism for 0.061 similar to 0.067 mm which higher than the design requirements and it is suitable for use in laser anti-counterfeit authentication system in production manufacturing engineering.