A heat pump mounting box for a heat pump dryer or washer-dryer, and a heat pump dryer or washer-dryer having the same are provided. The heat pump mounting box includes a base provided with an air suction port and a two-device mounting chamber; an air passage guide plate mounted on the base and defining, together with the base, an air guide passage that has a drying air inlet in communication with the air suction port and a drying air outlet in communication with the two-device mounting chamber; and a flock filter mesh assembly drawably mounted on at least one of the base and the air passage guide plate and located at the drying air outlet. The heat pump mounting box according to the present invention has good connection tightness and is easy to clean, thereby being less likely to cause air quantity loss and flock accumulation.