The invention discloses an electric pump acceleration sensor and a preparation method thereof, the acceleration sensor comprises a mass block and a suspended waveguide structure, and the mass block is arranged in the middle of the suspended waveguide structure; the suspended waveguide structure comprises a silicon substrate layer, a u-type gallium nitride layer, an n-type gallium nitride layer, a quantum well layer, a p-type gallium nitride layer, a p-type electrode and an n-type electrode which are sequentially arranged from bottom to top, the quantum well layer is arranged on one side of the upper surface of the n-type gallium nitride layer, and the silicon substrate layer supports the two ends below the u-type gallium nitride layer. According to the preparation method, the nitride microcavity with the suspended waveguide structure is prepared on a silicon substrate nitride epitaxial wafer by utilizing photoetching, ICP dry etching and silicon wet etching processes. According to the invention, the light source and the sensing device are focused on the gallium nitride suspended waveguide optical resonant cavity, and the prepared acceleration sensor can be subjected to high-density photoelectric integration and has higher resolution and sensitivity.