The invention provides a signal voltage difference control assistance system for processing speed signals and outputting signals, and belongs to a bicycle power supply controller system for difference assistance distribution of a front wheel and a back wheel which are used for supplying assistance power in a difference manner. The system comprises two wheels and two motors of a power-assisted bicycle and manual gear signal controllers, and also comprises a differential distributor, wherein the differential distributor comprises three modules which are successively connected; the first module is used for processing the values of the currents IA and IB of the signals in a comparing manner; the second module is used for processing the data of the first module in a model function manner by the set model function; the third module is used for inputting the average speed signal IS of a speed averager to a data distributor of the differential distributor, and respectively processing the control data by adding speed signal factors, so that the data obtained by the controllers A and B not only contain the factors of the IA and the IB, but also contain the factors of average speed signal IS. The system has the advantages that the different power supply control of the two motors of the front wheel and the back wheel of the power-assisted bicycle is realized, and the content of the differential control contains the previously set model function processing.