Objective Because intraocular lens（IOL）tilt and decentration have an effect on postoperative defocus，astigmatism and other refractive states as well as wavefront aberration，the results of IOL tilt and decentration measured by many methods have certain deviations. This paper provides a more accurate method for calculating the IOL tilt and decentration. Methods Based on anterior segment images of three cases with subluxation lens after operation，we collected the IOL surface data with three different methods. The IOL tilt and decentration values were obtained through image registration and the spherical surface fitting of the anterior and posterior surfaces of IOL，respectively. Results Based on the formula of IOL tilt and decentration，we obtained the IOL tilt angles，decentration values，the horizontal and vertical tilt angles collected by the three methods. The first method based on the spherical surface fitting was better than the other two methods. Conclusions To calculate the IOL tilt and decentration by spherical surface fitting of the IOL surface，we should choose the clearest image among images of each scanning rotated angle for collecting IOL surface data. This method can accurately analyze the IOL’s location.