The invention discloses a greenhouse compound heating system for integrating hot air, floor heating and warm water irrigation. The system comprises a fired coal hot air furnace, a hot air heat exchange chamber, a hot water heat exchange chamber, a floor heating pipe and a temperature adjusting tank; high-temperature gas generated by the fired coal hot air furnace enters the hot air heat exchange chamber and the hot water heat exchange chamber to respectively exchange heat with clean cold air to be heated in the hot air heat exchange chamber and clean cold water to be heated in the hot water heat exchange chamber; the cold air is heated to dissipate into a greenhouse by a hot air outlet; after the cold water is heated, one part flows into the floor heating pipe, and the other part flows into the temperature adjusting tank; the floor heating pipe heats soil of the greenhouse; the cold water is finally circulated into the hot water heat exchange chamber; and the hot water and the cold water in the temperature adjusting tank are mixed to form warm water for irrigation. The greenhouse compound heating system for integrating hot air, floor heating and warm water irrigation has the following beneficial effects: the all-directional and multi-angle effective greenhouse heating is realized; the utilization efficiency of heat energy is improved; and the excellent growth temperature is provided to crops.