A beams-mass structure, which is sensitive to the acceleration, is designed based on the SU-8 photoresist′s high aspect ratio imaging feature. Theoretical expressions are deduced for analyzing the relationships between acceleration and the deflection of the beams-mass structure, acceleration and the light intensity of Fabry-Pérot interference. Simplified calculation formulas are obtained and major influences such as the sensitivity and the natural frequency are discussed. The new beams-mass structure with the “卍” form is presented, and its parameters are analyzed and determined. The results show that the new SU-8 photoresist Fabry-Pérot acceleration sensor with “卍” structure improves the sensitivity vastly and has a good detection mode. The simulation results match to the theoretical analysis, which confirms that the designed structure can be applied in acceleration monitoring based on Fabry-Pérot interference theory.