A liquid reservoir includes a housing and a cover hermetically fixed to the housing, and further includes a flow guiding pipe having one end connected with the housing, and a filter assembly arranged in the housing and including first and second position-limiting assemblies, a filter member, and a molecular sieve. The first position-limiting assembly includes at least a first position-limiting member having a bottom portion, first and second protrusions. A part of an outer side wall of the flow guiding pipe is limited by and in cooperation with an inner side wall of the first protrusion which is located on an outer peripheral side of the part of the outer side wall of the flow guiding pipe. An outer side wall of the second protrusion is located on an inner peripheral side of a part of an inner sidewall of the housing.