The invention discloses a clamping activation method, applicable to an electric clamping device with wireless charging, the electric clamping device comprising a body and a wireless charging module, a control unit, and an electric clamping assembly, all disposed inside the body. The clamping activation method comprises: the control unit receiving a signal generated by the wireless charging module; the control unit activating the electric clamping assembly to clamp the electronic device according to the signal; and the control unit activating the wireless charging module to charge the electronic device. As such, the electric clamping device can automatically clamp the electronic device without installing additional sensing elements or switches.