A low-loss, compact, miniaturized and stable low-pressure CO2 cell is proposed based on hollow-core photonic crystal fiber (HC-PCF). In order to ensure the gas purity, the HC-PCF is firstly flushed with high-pressure high-purity CO2, and then connected with conventional optical fibers under the high-pressure environment. The insertion loss of HC-PCF gas cell is reduced efficiently by splicing one end of the HC-PCF to single-mode fiber (SMF) and connecting the other end of HC-PCF to multi-mode fiber with ceramic ferrule sleeve. By placing the HC-PCF into a vacuum chamber to decompress its pressure and subsequent sealing process, a HC-PCF low-pressure CO2 gas cell with the pressure less than 10 kPa is obtained. The insertion loss of this gas cell is approximately 3.5 dB, and the good air-tightness and long-term stability are observed. This kind of low-pressure HC-PCF gas cell may find broad applications in optical fiber gas sensing, laser frequency stabilization, and high resolution spectroscopy.