The　disruptive　blockchain　technology　is　expected　to　have　broad　applications　in　many　areas　due　to　its　advantages　of　transparency,　fault　tolerance,　and　decentralization,　but　the　open　nature　of　blockchain　also　introduces　severe　privacy　issues.　Since　anyone　can　deduce　private　information　about　relevant　accounts,　different　privacy-preserving　techniques　have　been　proposed　for　cryptocurrencies　under　the　UTXO　model,　e.g.,　Zerocash　and　Monero.　However,　it　is　more　challenging　to　protect　privacy　for　account-model　blockchains　(e.g.,　Ethereum)　since　it　is　much　easier　to　link　accounts　in　the　account-model　blockchain.　In　this　article,　we　propose　BlockMaze,　an　efficient　privacy-preserving　account-model　blockchain　based　on　zk-SNARKs.　Along　with　dual-balance　model,　BlockMaze　achieves　strong　privacy　guarantees　by　hiding　account　balances,　transaction　amounts,　and　linkage　between　senders　and　recipients.　Moreover,　we　provide　formal　security　definitions　and　prove　the　security　of　BlockMaze.　Finally,　we　implement　a　prototype　of　BlockMaze　based　on　Libsnark　and　Go-Ethereum,　and　conduct　extensive　experiments　to　evaluate　its　performance.　Our　300-node　experiment　results　show　that　BlockMaze　has　high　efficiency　in　computation　and　transaction　throughput:　one　transaction　verification　takes　about　14.2　ms,　one　transaction　generation　takes　6.1-18.6　seconds,　and　its　throughput　is　around　20　TPS.