An over-temperature protection method of a variable-frequency driver for air conditioners comprises the following steps: acquiring temperature information of a radiator module and a power module of avariable-frequency driver; when T1 is greater than or equal to Temp1 and smaller than Temp2, making the variable-frequency driver increase frequency slowly; when T1 is greater than or equal to Temp2 and smaller than Temp3, prohibiting frequency increase of the variable-frequency driver; when T1 is greater than or equal to Temp3 and smaller than Temp4, making the variable-frequency driver decreasefrequency slowly; and when T2 is greater than or equal to Temp4, making the variable-frequency driver decrease frequency quickly, wherein T1 is the temperature of the radiator module, T2 is the temperature of the power module, Temp1 is a temperature threshold for slow frequency rising, Temp2 is a temperature threshold for frequency rising prohibition, Temp3 is a temperature threshold for slow frequency falling, and Temp4 is a temperature threshold for quick frequency falling. The invention further provides a variable-frequency driver. According to the invention, the over-temperature state of the variable-frequency driver can be responded in time and corresponding protection can be provided, and the reliability is high.