Aiming at the lunar soil drill-sampling task, the bedding protection performances of two coring methods, hard tube coring and soft sack coring, are analyzed based on discrete element model. A curved surface slope method is proposed to describe the bedding information of the lunar soil sample. It can directly reflect the deformation of each layer of lunar soil sample distributed with drilling depth by curvefitted surface, and quantitatively illustrate the boundary between the slightly perturbed part and bedding damage part in each layer, and also the trend and degree of the bedding failure. Analysis results show that the soft sack can significantly protect the sample bedding information. The hard tube coring method destroys the bedding of outside sample seriously, and damages more layers, while there is no obvious difference in the scope that is slightly perturbed from the soft sack coring. Additionally, in both work conditions, the bedding information of surface regolith is damaged severely, which indicates that the lunar regolith on the surface has great follow-up property.