The invention discloses a water treatment device.The water treatment device comprises a shell, a base assembly and a filter element.The base assembly is arranged in the shell; the filter element is arranged in the shell and located at the top of the base assembly, and comprises an outer filter shell and an inner filter shell contained in the outer filter shell; an outer flow channel is jointly defined by the inner filter shell and the outer filter shell, a filter material is arranged in the inner filter shell to filter raw water, a first water passing through hole communicated with the inner filter shell and second water passing through holes communicated with the outer flow channel are formed in the inner filter shell, and a third water passing through hole communicated with the outer flow channel is formed in the outer filter shell.The water treatment device is simple and ingenious in structure, high in operational reliability and low in production cost.