Additive manufacturing technology can prepare highly flexible inclinometer sensors, i.e., the sensitivity, resolution, and range of the sensor can be designed and manufactured according to requirements. Therefore, this study develops a new type of inclinometer sensor based on fiber Bragg grating and the additive manufacturing technology. In order to verify the performance of the sensor, the measurement principle of the sensor is deduced, and the calibration and slope-model loading experiments are conducted. The experimental results show that the sensor's inclinometer sensitivity is 0.0824 (°)/pm, resolution is 12.14 pm/(°), and range is greater than 60°. The sensor is consistent with the slope test results of the linear variable differential transformer sensor, and the displacement difference is less than 0.08 mm.