An air conditioning terminal system for a large space, comprising: a first air conditioning device, a second air conditioning device, and an air conditioning terminal device, the air conditioning terminal device comprises a radiant coil, and air supply devices for conveying cold air or hot air into the large space; wherein, the radiant coil is buried inside a ground of the large space, the first air conditioning device is in communication with the radiant coil, and a fluid medium output from the first air-conditioning device is circulated in the radiant coil, energy of the fluid medium is first transmitted to the ground, and then radiates through the ground to the large space, thereby adjusting temperature of the large space; the air supply devices are installed at a bottom of the large space, and are in communication with the second air conditioning device; characterized in that: the air conditioning terminal device further comprises a liquid desiccant air conditioning unit for treating fresh air outside the large space and delivering the fresh air into the large space, and a plurality of dry fan-coils; the air supply devices are further in communication with the liquid desiccant air conditioning unit, the air supply devices output mixed air including the fresh air output from the liquid desiccant air conditioning unit and cold air or hot air output from the second air conditioning device to the bottom of the large space; the plurality of dry fan coils are fixed on the ground, and disposed near a side wall of the large space; a distance between the dry fan coils and the side wall of the large space is 0.5m to 10m. a first air conditioning device, a second air conditioning device, and an air conditioning terminal device, the air conditioning terminal device comprises a radiant coil, and air supply devices for conveying cold air or hot air into the large space; wherein, the radiant coil is buried inside a ground of the large space, the first air conditioning device is in communication with the radiant coil, and a fluid medium output from the first air-conditioning device is circulated in the radiant coil, energy of the fluid medium is first transmitted to the ground, and then radiates through the ground to the large space, thereby adjusting temperature of the large space; the air supply devices are installed at a bottom of the large space, and are in communication with the second air conditioning device; characterized in that: the air conditioning terminal device further comprises a liquid desiccant air conditioning unit for treating fresh air outside the large space and delivering the fresh air into the large space, and a plurality of dry fan-coils; the air supply devices are further in communication with the liquid desiccant air conditioning unit, the air supply devices output mixed air including the fresh air output from the liquid desiccant air conditioning unit and cold air or hot air output from the second air conditioning device to the bottom of the large space; the plurality of dry fan coils are fixed on the ground, and disposed near a side wall of the large space; a distance between the dry fan coils and the side wall of the large space is 0.5m to 10m. the air conditioning terminal device further comprises a liquid desiccant air conditioning unit for treating fresh air outside the large space and delivering the fresh air into the large space, and a plurality of dry fan-coils; the air supply devices are further in communication with the liquid desiccant air conditioning unit, the air supply devices output mixed air including the fresh air output from the liquid desiccant air conditioning unit and cold air or hot air output from the second air conditioning device to the bottom of the large space; the plurality of dry fan coils are fixed on the ground, and disposed near a side wall of the large space; a distance between the dry fan coils and the side wall of the large space is 0.5m to 10m.