The invention provides a defrosting control method of an air cooling refrigerator. The method comprises the steps of (S1) judging whether defrosting conditions are met or not, if the defrosting conditions are met, stopping the operation of a compressor for defrosting, and opening an air door of a refrigeration chamber to start a fan 1; and starting other chamber fans except for the refrigeration chamber; (S2) operating the fan 1 until the temperature of an evaporator sensor reaches a set temperature te, stopping the fan 1, and starting a defrosting heater; (S3) judging whether a set temperature for ending defrosting is satisfied or not, if the set temperature is satisfied, cutting off the defrosting heater to start the water dripping time; and (S4) judging whether the water dripping time is up or not, if the water dripping time is up, detecting the temperature of each chamber sensor; starting the compressor when any chamber reaches a machine starting point, opening the air door, starting the fan 1, and starting refrigeration of the refrigeration chamber; and then, judging whether the temperature te of the evaporator sensor reaches a set value td or not, if the temperature te of the evaporator sensor reaches a set value td, starting a fan 2 and a fan 3, and starting refrigeration through a freezing chamber. The method can reduce the defrosting energy consumption of the air cooling refrigerator to reduce the total energy consumption.