Aiming at the problem that it is difficult to use microscope to collect pictures from the large-size cutting sections of TFT -LCD glass，a corresponding glass section analysing equipment was designed，and the sliding spiral mechanism in the equipment was simulated and analyzed by Adams software and its structure was optimized.The results showed that the glass section analysing equipment was easy to operate and can quickly obtain the defect picture of large-size glass edge material section.After optimization and improvement ，the added torque value of sliding screw mechanism was reduced twice than that before optimization and improvement.