As a large-scale high-power and sophisticated laser facility, Shenguang-Ⅱ (SG-Ⅱ) is a milestone in the history of laser driver development in China. SG-Ⅱ laser facility has evoked comprehensive and essential leap-style improvements in laser engineering, laser technologies, fusion researches and fundamental physics researches. We provide brief introductions on the great innovative developments of engineering solutions and technologies during the project implementation, and we also list some of the numerous researches of international influence, which have been achieved based on the high-quality operation of SG-Ⅱ laser facility in the past 20 years. With the continuous great progresses of last decade and thanks to the support from leadership departments, facilities with delivery capacity of 104 J-level in nanoseconds, 103 J-level and petawatt-level in picoseconds, as well as 102 J-level and multi-petawatt-level in femtoseconds have been established, and will surely continue to operate as one of the key platforms on the researches of inertial confined fusion, strong field physics and high energy intensity physics in China.