The invention discloses an ecological air conditioning system with a fresh air function and two groups of phase change medium channels. The ecological air conditioning system comprises a cold, heat and fresh air supply system, working medium direct supply floor radiation heat transfer systems and an air source heat pump with a refrigerant conversion system; the roof and the floor of an indoor space are respectively provided with the working medium direct supply floor radiation heat transfer systems; the two working medium direct supply floor radiation heat transfer systems are respectively connected with two external interfaces of the air source heat pump with the refrigerant conversion system through connection pipes; the indoor space is respectively connected with the fresh air supply system through two air pipe connection pipes. The ecological air conditioning system is stable in work, small in input power, high in energy efficiency ratio, environmentally friendly, low in noise, low in cost and convenient to mount, is capable of automatically supplying mediums to be condensed to the floor system and supplying mediums to be evaporated to the roof system according to the commands sent by an indoor controller, and respectively supplies to two corresponding indoor phase-change heat transfer systems so as to realize floor heat supply in winter and roof cold supply in summer.