MEMS safety and arming device (SAD) with merits of small size and easy integration is one of the most promising candidates for the fuze to realize miniaturization, integration and intelligence. In this paper, a novel inertia-driven MEMS SAD with three independent safety features is proposed. The SAD placed perpendicular to the projectile axis is beneficial to reduce the size and improve the detonation energy transfer efficiency. The dynamic finite element simulations are carried out to study the mechanical responses of the device under dual-environment inertial loads. The response behaviors of the setback and centrifugal safety features and interrupter under different loads are elucidated and discussed. A series of experiments are performed to verify the simulation analysis results and investigate the safety and arming performances. The results indicate that the proposed MEMS SAD with small size and compact structure has successfully achieved safety and arming performances. The experimental results are in good agreement with the simulated analysis results.