The precision measurement of morphology of wafer by focusing and leveling measurement system is the key to high-quality exposure. The focusing and leveling measurement technology based on optical triangulation is widely used to measure wafer morphology by mainstream lithography manufacturers. In this paper, first, the measurement principle and system composition based on optical triangulation is introduced. Then, aiming at realizing high-precision and high-speed wafer morphology measurement, the key technologies and their evolution process of focusing and leveling measurement system are specially analyzed around the measurement mode, process adaptability and the corresponding imaging optical path. Finally, the improvement and optimization of focusing and leveling measurement system is pointed out in order to meet the requirements of extreme ultra-violet lithography vacuum environment.