In order to apply to S-Band (1-4.5 GHz) of wireless communication system, we designed and fabricated a high-insolating RF-MEMS switch by surface micromachining technology in this study. In terms of the micro switch, we performed the structural design, high frequency simulation, components process integration and high-frequency measurement in this study. Especially for making components be high-isolation, low-loss and low-driving voltage, we proposed the following three methods: (i) adjusting the space and width of the transmission lines to improve the RF performance; (ii) applying the stress imbalance, by using dual metal composite top electrode, to form a arched contact electrode and reduce the drive voltage efficiently; (iii) using non-isometric spring structure to stabilize the electrode movement of the components. Besides, we did the optimizing simulation for this study, which were supported by Ansoft-HFSS and ADS, in terms of the micro switch which has different structural design as mentioned above. The size of the optimized RF micro-switch which we developed for this study is only 145 £gm ¡Ñ 205 £gm. Switched from on-state to off-state, the component needs 36.5V drive voltage only. According to the result of the commercial network analyzer in 1-4.5GHz frequency range, the isolation rate of the components reaches -59.721dB while off-state; the insert los reaches -1.625dB while on-state.