For the high-speed and high-precision fabrication of complex three-dimensional micro-nano structures, a dual-beam laser direct writing lithography system based on the PPI technology is designed and developed. To meet different requirements, the system may operate in different modes at user options, including piezoelectric platform scanning mode, galvanometer scanning mode, and composite processing mode. By the accurate control of laser power and scanning speed, polymerized line-arrays attached on substrate surfaces with 64 nm linewidth and a group of suspended lines with 30 nm linewidth are obtained in the experiments. The maximum fabricating speed of our system reaches 50 mm/s. It is suitable for the efficient manufacturing of a variety of planar and three-dimensional micro-nano structures, and it provides a powerful scientific research tool for many research fields of micro-nano optics, micro-nano electronics, biology, and other disciplines.