A method for nonlinear compensation of background light voltage of position sensitive detector(PSD) based on neural network high accuracy linearization sub-block network integration interpolation is presented.In order to background light compensation over a full range,the neural network is trained to properly represent the nonlinear mapping between sensor readings and their outputs accurately at different background light.The experimental results show that the influence of background light fluctuation can be eliminated effectively,and a desired linear relationship between the sensor input and the neural network output can be obtained.