Aimed at a novel optical acceleration sensor a simple and useful micro spring-mechanical structure is designed.The structure is fabricated in a silicon substrate by MEMS technology.The elastic coefficient of the spring-arm and first-order natural frequency of the vibration system are analyzed by using energy method and simulated through the numerical simulator（ANSYS 8.0）of finite element method.In order to meet the performance requirement of the sensor

the parameters of micro spring-mechanical structure are calculated.The results indicate that the design is logical and feasible.The measuring range of the sensor determined by the calculated parameters is about ±395 m/s2 and the range of frequency is about 1

4

.5 kHz.