In the baseline design of the Circular Electron Positron Collider (CEPC) tracking system, the high position resolution(~100μm) Time Projection Chamber(TPC) would be as the main tracker detector integrated with silicon tracker and ECAL. Unlike the detector at International Linear Collider (ILC), the beam structure of CEPC is the continous mode, which determines the detector's operation without the ‘power-pulsing’, on both Higgs and Z-pole energy regions with the high rating.
To meet the critical physics requirements of the tracker, the new concept structure gaseous detector module as one option for the tracer detector has been developed and tested. In this talk, the deviation of position resolution was calculated by the space charge causing the track distortions in the drift chamber at Z pole run in CEPC, and the value was less than 10μm in the inner diameter of TPC detector. Some performance of the conceptual detector module was obtained. The energy resolution is better than 20% for 5.9 keV X-rays and it indicates that the continuous suppression of ions backflow ratio about 0.1% can be reached at the gas gain of about 5000. Aimed to the calibration and alignment of TPC module, the TPC prototype integrated with laser calibration system has been designed with 5000mm drift length and 200mm*200mm active readout. The on-going R&D activities and some preliminary results will also be briefly reported.