Standing in the forefront of the development of modern science and technology, Qian Xuesen put forward the thought and method of system engineering, applied them to the construction of socialist modernization, and created social system engineering (social engineering) method. Social engineering, in his view, is a scientific way to know society, change society, construct society and manage society. Qian Xuesens social engineering idea and his comprehensive integrated approach from the qualitative to the quantitative have great significance for the building of socialism with Chinese characteristics.