Attention is focused on fully automatic camera calibration, and a calibration method based on three-dimensional (3D) reference points is proposed. This method acquires camera parameters through three steps: automatic recognition, automatic matching and high-precision calculation, which only needs the coordinates of 3D points and the image. The method of calibration and the focal length coherence automatic matching algorithm are put forward under the condition of knowing the coordinates of camera center and the orientation of camera optical axis, respectively; and the minimal residual automatic matching algorithm is proposed using computation residual and reprojection residual as criterion, when there is no prior information. Numerical simulation and physical experimental results show the speediness, correctness and high precision of our automatic matching algorithms and fully automatic calibration model.