Most Fabry-Pérot (F-P) interferometers that with a gas-gap F-P cavity structure are usually limited by mirror adjustment, stability, and volume limitations. To address these limitations, a solid-gap F-P cavity structure was proposed. A simulation of the solid-gap F-P interferometer was conducted using the theory of multi-beam interference to determine the peak position of each level of interference fringe and the half-height full-width position. The impact of three factors on the imaging quality of the solid-gap F-P interferometer was analyzed, which were cavity length, reflectivity and refractive index of the solid-gap F-P cavity. And a 16 mm thick solid-gap F-P cavity sample was processed according to the requirements. In comparing the actual detection with the theoretical simulation, it was found that the deviation of the peak position of the first level fringe is better than 5 pixels, and the deviation of the other levels of fringe is better than 2 pixels. The two are in good agreement. This work validates the applicability and scalability of the solid-gap structure in interferometer imaging, completes the basic theoretical exploration of the solid-gap F-P interferometer, and provides a reference for relevant research and development.