The outbreak of the coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 has spread globally. SARS-CoV-2 enters human cells by utilizing the receptor-binding domain (RBD) of an envelope homotrimeric spike (S) glycoprotein to interact with the cellular receptor angiotensin-converting enzyme 2 (ACE2). We thoroughly studied the differences between the two RBDs of SARS-CoV and SARS-CoV-2 when they bind with ACE2 through molecular dynamics simulations. The peculiarities of the SARS-CoV-2 RBD are obvious in several aspects such as fluctuation of the binding interface, distribution of binding free energy on residues of the receptor-binding motifs, and the dissociation process. Based on these peculiarities of SARS-CoV-2 revealed by simulations, we proposed a strategy of destroying the RBD of SARS-CoV-2 by employing enzymatic digestion. This unique strategy is promising for developing a skin-friendly, nontoxic, and convenient disinfectant to protect people from infection by SARS-CoV-2.