A mechanism (100) for storing and releasing mechanical energy, which stores a low-power energy continuously inputted by a power transmission mechanism into an energy storage mechanism, and then controllably drives output in a high-power manner. The mechanism comprises a bracket (10), a supporting main shaft (11) arranged on the bracket (10), a driving gear (101) which sleeves over and rotates about the supporting main shaft (11), wherein arranged on one side of the driving gear (101) is at least one set of energy storage and release device (102). The mechanism (100) for storing and releasing mechanical energy is structurally simple and reliable. A light-weight high-efficiency drive mechanism may be fabricated by using a light-weight structural material or a composite material, which may store a large amount of low-power energy which is inputted continuously. The stored energy may then be released in a high-power manner by means of manual operations or smart electronic control, in order to drive equipment which require higher power to drive, or to be fed back to an original driving device by means of a designated transmission mechanism to be used as auxiliary kinetic energy. The mechanism features high operation efficiency and low energy consumption, and is thus high efficient in storing and releasing energy.