For micro piezoresistive sensors widely used in the traditional process, to improve the range and natural frequency means to increase the beam thickness and reduce stress;while to improve the sensitivity requires reducing the beam thickness,which are mutually contradictory.A four beam structure of the high overload micro piezoresistive accelerometers was designed for improvement on the basis of the traditional beam island structure.A complementary structure with combination of main beams and micro beams was adopted to improve the natural frequency and the range;at the same time,the sensitivity was also improved.A new design of extending beam was proposed at the end of the beam structure, which greatly reduced the stress concentration phenomenon and improved the ability of anti overload of the structure. Moreover,the damping was analyzed and piezoresistive element was designed,the feasible layout design scheme was given. Simulation result showed the indicators of the high overload micro accelerometer could meet the requirements with obvious advantages.