With　rapid　urbanization　in　China,　land　use　efficiency　(LUE)　and　related　sustainability　should　be　reasonably　evaluated　and　improved.　Studies　have　rarely　investigated　urban　LUE　and　lack　an　analysis　from　the　sustainability　perspective.　Long-term　analysis　can　help　identify　the　weaknesses　in　LUE　and　obtain　a　more　stable　evaluation.　Hence,　in　this　paper　we　develop　a　dynamic　data　envelopment　analysis　(DEA)　model　to　assess　urban　LUE　considering　the　time　dimension.　Differing　from　studies　on　traditional　static　DEA　models,　this　study　connects　the　observed　periods　by　creating　a　common　objective　function.　In　addition,　a　method　for　estimating　the　sustainability　of　urban　LUE　is　proposed　under　the　DEA　framework.　The　proposed　method　was　applied　to　34　major　Chinese　cities　over　a　3-year　period,　from　2015　to　2017.　The　results　reveal　that　urban　LUE　still　has　potential　for　improvement　in　most　cities.　There　was　a　distinct　difference　in　efficiency　among　eastern,　central,　and　western　cities　during　the　observed　period.　The　average　efficiency　was　higher　in　eastern　cities　than　in　central　and　western　cities.　The　potential　to　optimize　the　land　area　and　GDP　should　be　realized　with　more　efforts　by　most　cities　to　strengthen　LUE.　Additionally,　most　inefficient　cities　have　weak　performance　regarding　the　sustainability　of　LUE.　The　proposed　approach　enriches　the　sustainable　measurement　of　LUE.　Some　management　implications　are　provided　to　improve　urban　LUE.　The　empirical　findings　provide　important　support　for　sustainable　land　use　in　practice,　and　the　proposed　model　is　an　important　empirical　extension　of　the　DEA　method　in　the　land　management　field.