The utility model discloses a with indirect evaporation cooling family formula central air -conditioning system of dew point of gas heater combination, including setting up the indirect evaporative cooling air -conditioning unit of dew point outside the house, the indirect evaporative cooling air -conditioning unit of dew point is including the unit casing, is provided with air intake, air exit respectively on the relative both sides wall of unit casing, is provided with the blast gate in the air exit, has set gradually dew point indirect evaporative cooler, direct evaporative cooler, breakwater and the unit of airing exhaust according to flow direction behind the air admission in the unit casing, direct evaporative cooler leads to the pipe net and is connected with user's end, the gas heater that the premises set up. The utility model discloses an indirect evaporation cooling family formula central air -conditioning system of dew point combines gas heater to use, but implementation system winter and summer freely switched in two seasons, have the characteristics that the energy consumption is hanged down, refrigeration effect can produce environmental pollution well and not.