Greenhouse heating system

The utility model relates to a greenhouse heating system which comprises a rear wall and an arch-shaped ceiling paved with a plastic film, a mixed rear slope heat preservation layer connected with the arch-shaped ceiling is arranged above the rear wall, a heat preservation cotton quilt capable of being paved to the bottom of the arch-shaped ceiling is arranged at the top of the arch-shaped ceiling, and the bottom of the arch-shaped ceiling is connected with the top of a vertical front wall. An entrance door is arranged on one side of the arched ceiling, the other side of the arched ceiling is sealed by a plastic film, a ventilation air window is arranged above the entrance door, a heat accumulator is arranged at the bottom of the other side of the arched ceiling, a refrigerant pipeline in the heat accumulator extends out of the two sides and then returns to the heat accumulator through a front wall and a rear wall to form a loop, and a circulating water pump is arranged on the refrigerant pipeline. The wiring