A receiver dryer includes a first body and a second body, one end of the second body away from the first body defining first and second connecting ports. The receiver dryer includes a filter cartridge including a first mating portion, a second mating portion, and a filter part at a middle portion; the first mating portion fits with an inner wall of the second body, one space allowing refrigerant to flow is formed between the filter part and the inner wall of the second body, the second mating portion is connected to the second connecting port, the space between the filter part and the inner wall of the second body communicates with the first connecting port, an inside of the filter part communicates with the second connecting port via the second mating portion, and refrigerant is filtered at least once when flowing between the first and second connecting ports.