A heat pump dryer includes a main casing having an air inlet channel and an air outlet channel, a compressor, a first heat exchanger positioned in the air inlet channel, a second heat exchanger positioned in the air outlet channel, a fan provided in the air inlet channel, and an energy efficient heat exchanger. The energy efficient heat exchanger has a first portion partially exposed to the air inlet channel, and a second portion partially exposed to the air outlet channel. Air is arranged to enter the air inlet channel to sequentially perform heat exchange with the first portion of the energy efficient heat exchanger and the first heat exchanger. Air passing through the air inlet channel is arranged to enter the air outlet channel to sequentially perform heat exchange with the second portion of the energy efficient heat exchanger and the second heat exchanger.