A miniature fast charging and discharging circuit, including a power supply, a pre-stage boost auxiliary circuit, a bidirectional flyback circuit and an output capacitor. Input and output terminals of the pre-stage boost auxiliary circuit are respectively connected to the power supply and an input terminal of the bidirectional flyback circuit. The output capacitor is an output terminal of the bidirectional flyback circuit. The pre-stage boost auxiliary circuit includes a third switching MOSFET and a primary high-voltage storage capacitor connected in parallel with the power supply. When energy of the bidirectional flyback circuit reversely flows, the current cannot flow from the drain to the source, the current is stored in the primary high-voltage storage capacitor. Then, voltage of two ends of the primary high-voltage storage capacitor increases, and the charging time and the discharging time are simultaneously reduced, thereby accelerating the repeated charging and discharging speed of a dielectric elastomer.