Due to the limited space of TBM launching area of Haiboqiao Station on Qingdao Metro Line No. 1, the separate launching technology of doubleshield TBM is adopted to realize construction function. The backup system is improved to realize separate launching of TBM with the lowest cost; and the basic separate launching scheme is discussed. The analytical results show that: (1) The basic backup systems needed for separate launching of doubleshield TBM include high/low voltage power supply and control system, water cooling system, hydraulic system, lubrication system, grease sealing system, air compression system, back filling and grouting system. (2) By lengthening the pipelines and cables, the doubleshield TBM can be disconnected at any position between the main body and the backup system or between the main body and part of backup system.