Disclosed is a mechanical energy accumulating and releasing mechanism. The mechanical energy accumulating and releasing mechanism can store low-power energy, which is continuously input by a power transmission mechanism, into an energy accumulating mechanism and can drivingly output the energy in a high-power manner. The mechanical energy accumulating and releasing mechanism comprises a frame, a support main shaft arranged on the frame, and a driving wheel sleeving the support main shaft and rotating around the support main shaft; one side of the driving wheel is provided with at least one group of energy accumulating and releasing units. The mechanical energy accumulating and releasing mechanism is simple and reliable in structure, when made from light structural materials or composite materials, can be light in weight and high in efficiency; the mechanical energy accumulating and releasing mechanism can store continuously-input low-power energy, and under manual operation of intelligent electric control, release the accumulated energy in the high-power manner to drive equipment requiring high power, or feed the energy back to an original driving device as assistant energy through a special transmission device. The mechanical energy accumulating and releasing mechanism is high in operational efficiency, low in energy consumption and accordingly high in energy accumulating and releasing efficiency.