The invention belongs to the technical field of air conditioners, and specifically relates to a defrosting control method for an air conditioner. In order to increase the defrosting efficiency for theair conditioner, the defrosting control method for the air conditioner aims at the air conditioner with an outdoor unit which is provided with double fans. The method comprises the following steps ofafter the air conditioner enters a defrosting mode, controlling an upper fan and a lower fan to stop rotation; after a first set time, if I(lower) is not less than 1.1Ie and not greater than 1.2Ie, and I(upper) is greater than Ie and less than 1.1Ie, only controlling the upper fan to reversely rotate for a second set time; after the first set time is past, if I(lower) is greater than I(upper) andless than 1.1Ie, and I(upper) is greater than Ie, controlling the lower fan to reversely rotate for the second set time, and controlling the upper fan to reversely rotate for a third set time; and after the first set time is past, if I(lower) is greater than I(upper) and less than 1.1Ie, and I(upper) is equal to Ie, only controlling the lower fan to reversely rotate for the second set time. According to the defrosting control method for the air conditioner, the upper fan and / or the lower fan are / is selectively controlled to reversely rotate according to the I(upper) and the I(lower), and thena frost layer is accurately blown off, so that the defrosting efficiency for the air conditioner is greatly increased.