The switch pressing generator is capable of converting pressing actions into electrical energy, supplying power for wireless key switches, which holds significant application value in green smart homes. This paper introduces an electromagnetic principal impact generator and proposes a bistable conversion structure. During the two steady-state transfers, the magnetic field lines in the coil undergo sudden changes in the opposite direction and the coil generates induced electromotive force pulses. Finite element software was employed to analyze the magnetic field distribution of the bistable structure, and the dimensions of the coils and iron core were optimized accordingly. The results show that the magnetic field lines in the two stable states of the coils have opposite directions, and the induced electromotive force increases almost linearly with the dimensions size. A prototype generator was fabricated and assembled. Experimental analysis reveals that the generator can produce an output voltage of up to 30V, generating an electrical energy of 1469 μJ. This provides sufficient power supply for wireless sensor network nodes and wireless switches, enabling green and environmentally friendly self-sufficient operation.