Heat pump grain dryer capable of recycling waste heat

The invention discloses a heat pump grain dryer capable of recycling waste heat. The heat pump grain dryer comprises a box body, a fan blade arranged in the left end of the box body, an evaporator arranged on the right side of the fan blade, a first electric regulation valve arranged on the right side of the evaporator, a condenser arranged on the right side of the first electric regulation valve, a refrigerant conveying pipe connected with the evaporator and the condenser, and a throttling device, a liquid storage tank and a compressor which are arranged on the refrigerant conveying pipe, a second electric regulation valve arranged on the right side of the condenser, an air outlet formed in the top of the box body and an air returning hole formed in the right side of the air outlet. According to the heat pump grain dryer, the first electric regulation valve is used for regulating dehumidification air exhaust amount; the second electric regulation valve is used for regulating fresh air feeding amount; the fan is used for regulating air supply rate; the first electric regulation valve, the second electric regulation valve and the fan can be combined to regulate the air heating efficiency of the condenser, thereby discharging air at constant temperature; a circulation air channel is formed by the air outlet and the air returning hole; the discharged waste heat can be recycled; the air heating effect of the condenser is improved; the energy-saving effect is achieved; the performance ratio of a host is increased.