To address the issue of inaccurate measurement data due to electromagnetic interference in traditional electronic and magnetic field angle sensors, this paper introduces a reflective optical fiber angle sensor. The Angle measurement is carried out by converting reflected optical fiber ranging into Angle, and the optical fiber Angle sensor model with STM32 as the main control is built. The voltage-angle characteristic curve is drawn by recording the corresponding relationship between the rotation Angle of the Angle sensor and its output voltage. However, due to the interference of the sensor′s mechanical structure and external environment, the nonlinear error of the volt-angle characteristic curve is relatively high. Therefore, the least square method is used to analyze the nonlinear error of the optical fiber Angle sensor. The nonlinear error of the sensor is calculated by the experimental simulation as 16.11%, indicating that the nonlinear error of the sensor is relatively high. So the nonlinear compensation model is established by using table lookup method. The experiment shows that the nonlinear error of the sensor can be reduced to 8.57% and increased by 7.54 percentage points by using table lookup method.