Focused on the on-orbit calibration problem of the wide field of view star sensor, a novel calibration model based on vector observations is proposed. The model uses 3 Rodrigues parameters, instead of Euler angles, as the ex-terior parameters to simplify the calculation, and complete the joint solution with intrinsic parameters and third order distortion parameters. Simulation shows that it has a higher accuracy than the traditional model with Euler angles. In case of a standard deviation of 0.05 pixels star point error, the model can still accurately calculate the camera parameters and the angle error after calibration is 0.483 arcsecond, and the mean residual errors are 0.019 pixels in x direction and 0.016 pixels in y direction. Furthermore, the initial parameters are simpler and there is no need to set initial values. Its accuracy is further verified by actual star maps of ZY-3 satellite, and result shows that it can improve the calibration accuracy largely. To further improve the calibration accuracy, higher pre-cision centroid algorithm is recommended in actual applications.