In order to estimate the calibration error, analyze the factors affecting the calibration error, and guide the camera calibration system engineering design before the calibration system design, we propose a new algorithm model for the P4P camera calibration algorithm. This model solves the problem that the azimuth, pitch angle and roll angle are coupled to each other, and makes the attitude angle solution only related to the camera internal parameters and the image coordinates of feature points. On this basis, the model of error analysis is built which can theoretically analyze the influence of image position errors, aberration, principal point, focal length, and locations of feature points on calibration of attitude angles. The simulation and experiment are carried out. The conclusion hints that the data of simulation and experiment of calibration accuracy are consistent and the error analysis model is accurate and valid. The model can guide the design of calibration system and has great engineering application value.