A muffler, comprising: a housing , the housing defining a cavity, a gas inlet , and a gas outlet , the gas inlet and the gas outlet being respectively in communication with the cavity; and a partition member disposed in the housing , the partition member partitioning the cavity into a resonant cavity and a muffling cavity that are isolated from each other, the resonant cavity being in communication only with the gas inlet , the muffling cavity being in communication with both the gas inlet and the gas outlet ; the partition member comprises a first partition plate , the first partition plate partitions the cavity into the resonant cavity and the muffling cavity, a gas inflow channel member in communication with the gas inlet and the muffling cavity is disposed in the housing , and a first through hole in communication with the resonant cavity is defined on the gas inflow channel member ; the muffling cavity comprises a plurality of muffling chambers, characterized in that the partition member comprises a third partition plate and a fourth partition plate disposed at an angle with respect to each other, to partition the muffling cavity into the plurality of muffling chambers, the third partition plate is joined to the first partition plate , the plurality of muffling chambers comprises a first muffling cavity, a second muffling cavity, a third muffling cavity, and a fourth muffling cavity along a gas flowing direction, the first muffling cavity is in communication with the gas inflow channel member , and the fourth muffling cavity is in communication with the gas outlet , gas entering the cavity from the gas inlet is capable of sequentially passing through the first muffling cavity, the second muffling cavity, the third muffling cavity, and the fourth muffling cavity and flowing out from the gas outlet . a housing , the housing defining a cavity, a gas inlet , and a gas outlet , the gas inlet and the gas outlet being respectively in communication with the cavity; and a partition member disposed in the housing , the partition member partitioning the cavity into a resonant cavity and a muffling cavity that are isolated from each other, the resonant cavity being in communication only with the gas inlet , the muffling cavity being in communication with both the gas inlet and the gas outlet ; the partition member comprises a first partition plate , the first partition plate partitions the cavity into the resonant cavity and the muffling cavity, a gas inflow channel member in communication with the gas inlet and the muffling cavity is disposed in the housing , and a first through hole in communication with the resonant cavity is defined on the gas inflow channel member ; the muffling cavity comprises a plurality of muffling chambers, characterized in that the partition member comprises a third partition plate and a fourth partition plate disposed at an angle with respect to each other, to partition the muffling cavity into the plurality of muffling chambers, the third partition plate is joined to the first partition plate , the plurality of muffling chambers comprises a first muffling cavity, a second muffling cavity, a third muffling cavity, and a fourth muffling cavity along a gas flowing direction, the first muffling cavity is in communication with the gas inflow channel member , and the fourth muffling cavity is in communication with the gas outlet , gas entering the cavity from the gas inlet is capable of sequentially passing through the first muffling cavity, the second muffling cavity, the third muffling cavity, and the fourth muffling cavity and flowing out from the gas outlet . <EOS>