Abstract: Based on the practice of combined TBM used for the Chongqing Metro line 6, this paper analyzes the characteristics and engineering adaptability of the combined TBM. In addition it describes in detail: the key techniques used in the designs of the lining section and the supported parameters, the extra-deep shaft and supported parameters, and the micro-disturbance control of the combined TBM construction under the buildings. All of these elements confirm the rationality and improvement of these design proposals.