In order to investigate characteristics of sensors based on all-solid-state photonic bandgap fiber (AS-PBF), a special optical fiber laser based on two-taper mode interference is prepared by fabricating two taper fibers in an AS-PBF on an interval with a splicer. Compared to the conventional single mode fibers or index-guiding photonic crystals, AS-PBF has a lower effective index in the core and a higher effective index in the cladding. According to the theoretical analysis and experimental verification, the temperature and axial stress response of the structure are investigated. Results show that the measured sensing sensitivities are about 0.063 nm/°C for temperarure and －1.74 nm/N for the axial stress, respectively. Compared with the long-period grating and Bragg grating, a two-tapers modal interferometer based on all-solid photonic bandgap fiber has a much compact device size and a simple fabrication, and it has wide application prospects in the filed of optical fiber sensing.