The structure design of angular position sensitive detector (APD) utilizing semiconductor′s lateral photo electric effect is introduced. A finite-element method (FEM) is adopted to analyze and calculate the output characteristics of APD, such as linearity, angular precision and response sensitivity. Based on FEM simulation, this APD design can achieve high linearity (<0.04%) and high precision (~20″) for angular measurement in the range of 90°. At last, the factors that influence the precision of measuring angle including electric parameters of material and model structure parameters, such as resistance and electrode, are analyzed. By optimizing material and structure, the APD can achieve higher linearity (<0.01%) and angle resolution (<1″) and be used in angular measurement with high resolution.