In order to meet the requirements of fast autofocus based on machine vision in industrial inspection systems, a new type of laser-based and high-speed embedded autofocus system is put forward. The design combines the characteristics of laser and visible light without affecting each other in the same optical path and the capabilities of Digital Signal Processing (DSP) high-speed image processing, and controls motion actuator to achieve fast and stable focusing of microscope in the industrial inspection systems by inspecting the laser facula information reflected back by optical path designed specially. Moreover, the design improves traditional method defects of slow accuracy and speed in TFT-LCD optical inspection system, such as based on the passive image processing and active range auto-focus measurement. Test results show that the new focusing system greatly shortens the focusing time, increases the control precision of the focusing system, and meets practical application requirements in the industrial optical inspection systems.