Secondary　aluminum　dross　(SAD)　is　regarded　as　a　solid　waste　of　aluminum　recycling　process　that　creates　serious　environmental　and　health　concerns.　However,　SAD　can　also　be　used　as　a　good　source　of　aluminum,　so　that　utilizing　the　SAD　for　the　production　of　valuable　products　is　a　promising　approach　of　recycling　such　waste.　In　the　present　work,　a　novel　eco-friendly　three-step　process　was　proposed　for　the　synthesis　of　cryolite　(Na3AlF6)　from　the　SAD,　and　it　consisted　of　(1)　water-washing　pretreatment　of　SAD,　(2)　extraction　of　Al　component　via　pyro-hydrometallurgy,　including　low-temperature　alkaline　smelting,　water　leaching　and　purification　of　leachate　in　sequence,　(3)　precipitation　of　cryolite　from　the　purified　NaAlO2　solution　using　the　carbonation　method.　By　analysis　of　the　parameter　optimization　for　each　procedure,　it　was　found　that　the　maximum　hydrolysis　efficiency　of　aluminum　nitride　(AlN)　in　the　SAD　was　around　68.3%　accompanied　with　an　extraction　efficiency　of　Al　reaching　91.5%.　On　this　basis,　the　cryolite　of　high　quality　was　synthesized　under　the　following　optimal　carbonation　conditions:　reaction　temperature　of　75　°C,　NaAlO2　concentration　of　0.11　mol/L,　F/(6Al)　molar　ratio　of　1.10,　and　99.99%　CO2　gas　pressure,　and　flow　rate　of　0.2　MPa　and　0.5　L/min　respectively.　The　formation　of　Na3AlF6　phase　can　be　detected　by　XRD.　The　morphological　feature　observed　by　SEM　revealed　that　the　as-synthesized　cryolite　had　a　polyhedral　shape　(~1　μm　size)　with　obvious　agglomeration.　The　chemical　composition　and　ignition　loss　of　the　as-synthesized　cryolite　complied　well　with　the　requirements　of　the　Chinese　national　standard　(GB/T　4291-2017).　©　2020　by　the　authors.