The invention relates to a variable-frequency power source based on the control of a digital signal processor, which comprises a switch power source module, a control circuit, a circuit for isolating and shaping pulse-width modulating signal, IPM inverting circuits, a circuit for detecting and protecting busbar voltage, a rectification input slow-start circuit, a communication circuit, an interface circuit for isolating and inputting parallel signals and an human-computer interface circuit for displaying the key. The invention adopts the structure of a single digital signal processor (DSP) coupled with the double IPM inverting circuits, provides two paths of independent variable-frequency power sources for two sets of asynchronous motors at the same time and carries out independent speed regulations to the two sets of asynchronous motors. The variable-frequency power source of the invention has the advantages of small volume, low power consumption, high reliability and being convenient for bulk production, etc., and adopts an appropriate switch frequency and an advanced voltage space vector pulse width modulation algorithm (SVPWM), thereby lowering the noise during the operation of the asynchronous motors and increasing the voltage utilization rate, with obvious effect on energy saving.