The high-pressure nitrogen-filling and the leaking characteristics for hollow-core photonic crystal fiber (HC-PCF) were investigated experimentally and analyzed with the micro-pipe flow theory. The results show that, the nitrogen-filling speed for the HC-PCF is slow, and the time required for building the pressure equilibrium in the HC-PCF may be shortened efficiently by reducing the volume of the outlet cavity. When a HC-PCF with the length of 9 m was nitrogen-filled with 3.03×106 Pa after one of its ends has been spliced to the single-mode fiber (SMF), the time required for building such a pressure equilibrium was smaller than 4 hours. The leaking speed from one end of a 3.03×106 Pa nitrogen-filled HC-PCF and its evolution with the time were measured experimentally, and the results may be used for evaluating the final pressure of the gas cell. Finally, a HC-PCF nitrogen-filled cell with a pressure of 1.73×106 Pa and an insertion loss of 9.3 dB was manufactured.