A picosecond laser machining system is designed, which can output 355、532、1064 nm picosecond laser. The maximum single pulse energy is 1.5 mJ and the pulse width is 9.12 ps. Through the axial aberration compensation design, the maximum distance of axial focus compensation is 0.4 mm, the diameter of minimum focal spot is 3 μm and the maximum peak power density is 0.6×1015 W/cm2. With this system, the machining experiment of different wavelengths and different materials is completed. The results show that 1064 nm picosecond laser can be used to cut mobile phone screen, 532 nm picosecond laser can be used to product photoelectricity detector and 355 nm picosecond laser can satisfy micro-machining requirements of metal materials.