The invention discloses a multi-split air conditioner system suitable for a southern building inner zone and a cold supply method. The multi-split air conditioner system is characterized in that a multi-split air conditioner outdoor unit, a multi-split air conditioner indoor unit, a multi-split air conditioner fresh air treatment unit, an air supply machine, an air outlet machine, a sensible heatexchanger and a temperature sensor are included; the multi-split air conditioner fresh air treatment unit and the air supply machine are connected through an air supply pipe in parallel; the multi-split air conditioner outdoor unit transmits heat or cooling capacity to the multi-split air conditioner indoor unit or the multi-split air conditioner fresh air treatment unit through a refrigerant in arefrigerant pipe, and indoor air is exhausted out of a room sequentially through an air outlet, an air outlet pipe and the air outlet machine. Refrigeration is efficient in summer, outdoor low-temperature air is sufficiently utilized for eliminating indoor surplus heat in spring, autumn and winter; a displacement ventilation system is utilized for improving the indoor air quality and the indoor personnel comfort degree; the sensible heat exchanger is utilized for conducting heat recycling on indoor energy, energy consumption of the multi-split air conditioner indoor unit is reduced, the starttime of the multi-split air conditioner indoor unit is shortened, the temperature sensor is used for adjusting the rotation speed of the air supply machine and the air outlet machine in spring and autumn, and the whole system is efficient and capable of saving energy.