The invention discloses a multifunctional solar heat collector. Solar energy near a greenhouse can be fully utilized, and solar energy radiated to the multifunctional solar heat collector is used for increasing the air temperature in the greenhouse. When the air temperature in the greenhouse meets the requirements, the solar heat collector can utilize surplus solar energy to increase the water temperature, and the surplus solar energy can be stored in water. When the air temperature in the greenhouse decreases, heat stored in the hot water is released by the multifunctional solar heat collector into air of the greenhouse so as to increase the temperature in the greenhouse.