Objective To study the precise method of IOL power calculation in traumatic cataract with comeal scar.Methods In this prospective study,51 eyes of 51 cases of traumatic cataract with corneal scar were underwent phacoemulsification and IOL implantation by identical operator.The preoperative corneal curvature value surveyed by Orbscan-Ⅱ corneal topograph and the corresponding IOL power which was caculated with SRK/T formula were collected,as experimental group.Meanwhile the normal ocular corneal curvature value surveyed by manu-keratometer and the corresponding IOL power were also collected,as control group(IOL were implanted according to the results in operation).3 months after operation the cases accepted computer and retinoscopy optometry examination.The results of refractive error were converted into the degree of equivalent spherical glass,then the degree×1.25 was added to the IOL power which had been implantated,the final results were as the standarded group.At last,these data were compared.Results The control group compared with the experimental group,the data were significant difference.The result was same between the control group and the standard group.But the experimental group compared with the standard group,the data were not different.Conclusions Caculating IOL power with the coneal curvature value surveyed by OrbscanⅡ corneal topography is a better method to traumatic cataract with corneal scar.it can reduce the refractive error after operation.