To solve the problem of poor heating performance of air source heat pumps when the air temperature is relatively low, this paper proposes a flat heat pipe and heat pump heating device based on solar energy. The device can store solar energy and continuously replenish the heat pump. The performance of the device is studied through experiments and simulation calculations. The results show that the difference in temperature between the evaporating section and the condensing section of the flat heat pipe is about 1°C, which shows that the heat pipe has good thermal conductivity. The device can produce a temperature rise of 7~61°C for the air entering the heat pump, which can realize the purpose of heat replenishment for the heat pump. Under the premise of no heat supply, the device can continuously heat -5°C fresh air to 5°C within 3.6 hours through the storage of solar energy. It shows that the device has good heat storage capacity. The above research shows that the device can realize the function of continuous replenishment of air source heat pump by solar energy, and has certain practical application value.