Inspired　by　the　conformational　change　of　the　enzyme-substrate　complex　in　molecular　dynamics　(MD)　simulation　with　distance　restriction,　we　propose　a　strategy　for　identifying　the　engineering　targets　based　on　the　comparative　analysis　of　enzyme-/substrate-binding　modes　in　MD　simulations　with　and　without　distance　restriction　(prereaction-state　simulation　and　free-state　simulation).　Taking　the　short-chain　dehydrogenase/reductase　(SDR)　mutant　EbSDR8-G94A/S153L　(Mu0)　with　poor　activity　toward　bulky　aryl　ketones　as　an　example,　H145　and　Y188　were　identified　as　the　engineering　targets　due　to　the　distinct　conformation　difference　in　the　two　simulation　modes.　To　break　the　＂beam＂　structure　formed　by　these　residues　at　the　entry　of　cavity　C2　in　free-state　simulation,　the　substrate-binding　pocket　was　reconstructed,　and　meanwhile　the　relative　size　of　cavities　C1　and　C2　was　modulated　to　improve　the　enantioselectivity.　In　this　way,　mutants　for　efficient　asymmetric　reduction　of　o-halogenated　acetophenones,　propiophenones,　aromatic　ketoesters,　and　diaryl　ketones　were　designed,　delivering　chiral　alcohols　with　＞99%　conversion　and　＞98%　ee.　The　effectiveness　of　this　design　strategy　was　also　validated　by　the　successful　redesign　of　PpYSDR,　generating　a　variant　for　efficient　reduction　of　(4-chlorophenyl)　2-pyridyl　ketone　into　the　S-product　with　＞99%　conversion　and　96%　ee.　MD　simulations　suggested　a　suitable　binding　pocket　with　proper　energy　contribution　as　the　ubiquitous　mechanism　for　the　improvement　of　activity　and　enantioselectivity　toward　substrates　with　varied　structures.　The　success　in　this　study　provides　hints　for　the　rational　design　of　alcohol　dehydrogenases/reductases　with　both　a　broad　substrate　spectrum　and　high　enantioselectivity.　Copyright　©　2019　American　Chemical　Society.