The invention relates to a method for intelligently controlling the frequency of a variable-frequency air-conditioner, comprising the following steps of: (1) reading the temperature difference delta T of the set temperature of the variable-frequency air-conditioner and indoor ambient temperature and calculating a frequency value Ft according to the temperature difference by a frequency converter;(2) reading each running parameter of the variable-frequency air-conditioner and controlling the air-conditioner to stop, or limit the frequency, or reduce the frequency or normally run according to the parameter value by using the frequency converter; (3) if each parameter displays that the frequency needs to be limited, ensuring the adjusted frequency Fobj to be equal to Ft, and if each parameter displays that the frequency needs to be reduced, ensuring the Fobj to be equal to Ft-delta T; (4) if each parameter displays the normal running, adjusting the frequency Ft according to the variation of the delta T in a certain time t1; and (5) outputting the Fobj to a driver of a variable-frequency compressor of the air-conditioner by using the frequency converter. The method can improve the comfort level, the using effect and the service life of the variable-frequency air-conditioner.