The invention discloses a multifunctional input method and system for a driving frequency converter. The multifunctional input method comprises the following steps: 1) respectively numbering all the digital quantity input functions in the driving frequency converter in advance, thereby acquiring function numbers respectively corresponding to the digital quantity input functions, performing logic numbering on input signals of multi-sectional digital quantity input functions in the digital quantity input functions, and causing each logic number of the input signals to be respectively corresponding to different preset values; and 2) receiving the assignation for the function numbers in real time, configuring the input end as a corresponding digital quantity input function according to the assigned function numbers, and controlling the driving frequency converter according to the configured digital quantity input functions and the data inputted by the input end. The system comprises an input function numbering module and a multifunctional input module. The multifunctional input method provided by the invention has the advantages that the realizing method is simple, the required cost is low, various digital quantity input functions can be integrated into one input port and the quantity of the input port is greatly reduced.