To　address　privacy　concerns,　data　in　the　blockchain　should　be　encrypted　in　advance　to　avoid　data　access　from　all　users　in　the　blockchain.　However,　encrypted　data　cannot　be　directly　retrieved,　which　hinders　data　sharing　in　the　blockchain.　Several　works　have　been　proposed　to　deal　with　this　problem.　However,　the　data　retrieval　in　these　schemes　requires　the　participation　of　data　owners　and　lacks　finer-grained　access　control.　In　this　paper,　we　propose　an　attribute-based　keyword　search　scheme　over　the　encrypted　blockchain,　which　allows　users　to　search　encrypted　files　over　the　blockchain　based　on　their　attributes.　In　addition,　we　build　a　file　chain　structure　to　improve　the　efficiency　of　searching　files　with　the　same　keyword.　Security　analysis　proves　the　security　of　the　proposed　scheme.　Theoretical　analysis　and　experimental　results　in　performance　evaluation　show　that　our　scheme　is　feasible　and　efficient.