A hollow-core photonic bandgap fiber (HC-PBGF) is an ideal option for realizing an online fiber cavity in integrated optical networks because of its capability of light transmission through the hollow core. In this work, a commercial arc splicer was used for directly splicing an HC-PBGF (HC-800-02) to a single-mode fiber (780-HP), and the effects of several parameters on the fusion quality were analyzed in detail. An HC-PBGF-based low-loss fiber cavity with a length of approximately 1 m was demonstrated, with a total insertion loss of 2.59 dB.