This paper proposes a breakdown pixels extraction architecture for single photon avalanche diode (SPAD) based faint light detection systems. The proposed extraction circuit detects the breakdown pixels and only their addresses are readout. Therefore, under the faint light environment, this SPAD-based sensor significantly improves the data readout efficiency. A test-of-concept chip with a 15x15 SPAD pixels array was fabricated in a 0.18 um 1P5M standard CMOS process and pinhole diffraction patterns were successfully captured thanks to the high sensitivity of the SPAD sensor.