The management mode of scientific researchdesignconstruction integration is adopted in Line No. 4 project of Ningbo Metro; and the technical system of railway transit quasirectangular shield tunnel is developed. By adopting the abovementioned technical system, the problems of segment design and structural optimization have been solved. The fullface cutterhead and driving system, shield hinging and sealing technology and ringarm segment erector have been developed. The simultaneous grouting technology, segment erection simulation and technical optimization and shield axial line control have been studied. A new kind of singletube doubleline tunnel will appear to solve the problem of limit underground space in core districts of cities in China.