In this paper, a simple sensor with high sensitivity based on tapered hollow fiber was designed and fabricated, and its temperature and strain characteristics were measured by experiments. Firstly, a section of hollow fiber was fused between two standard single-mode fibers by using the optical fiber fusion splicer, and then a discharge was applied to the middle of the hollow fiber, while two stepper motors were used to apply a certain tension at both ends of the single-mode fiber, which led to the conversion of Fabry-Perot interferometer to Mach-Zehnder interferometer. The experimental results show that the temperature sensitivity of the fiber optic sensor is improved from the theoretical value of 0.85 pm/℃ to 69.1 pm/℃ by approximately 81.3 times and the axial strain sensitivity is up to 3.6 pm/με after the tapered process. The device has the characteristics of small size, simple structure and high sensitivity, and has a broad application prospect in aerospace, medical monitoring and other fields.