In the study, we use TSMC 0.18μm CMOS-MEMS to design the the micro-electromechanical variable capacitor with easy fabrication, high-change rate and low operating voltage. It is aslo compatible with CMOS process. The main structure includes the symmetric comb electrodes, spring top electrode, high dielectric constant materials and flatbed bottom electrode. The operating principle is to use static force to drive the upper electorde with high dielectric constant material. when the voltage is applied on the top and bottom electrodes, the top electrode move downward to increase the dielectric constant between the comb electrodes, which increases the capacitance of variable capacitor.