A high accuracy calibration method for errors resulted from aberration in long focal length measurement, is presented. Generally, Gaussian equation is used for calculation without consideration of the errors caused by aberration. However, the errors become the key factor affecting the accuracy in the measurement system, based on divergent light, of a large aperture and long focal length lens. An effective way is proposed to calibrate the errors, with detailed analysis of the long focal length measurement based on divergent light and Talbot interferometry. Aberration errors are obtained by numerical method and compared with results simulated by Zemax. Then, auto-correction is achieved with the help of Visual C++ software and the modified measurement results of 13500 mm focal length lens and 31251 mm focal length lens reveal that the relative accuracy is better than 0.007% and 0.022%, respectively. By comparing the modified relative accuracy with relative accuracy obtained in interferometer measurement, the proposed method is proved to be highly effective and reliable.