Traditional MEMS electrostatic actuators have the problems of high actuation voltage and overshoot oscillation. The movable electrode oscillates continuously before stabilizing at the equilibrium position; hence, satisfying the comprehensive requirements of variable capacitors, optical switches, and other applications is difficult. To solve the above problems, this study adopts the design of a variable stiffness cantilever beam. With the characteristic of increasing stiffness with travel, the oscillation phenomenon is suppressed. The actuation voltage is effectively reduced, and the transient time is shortened. The simulation and experimental results show that when the stiffness of the cantilever beam increases from 5N/m to 35N/m, the transient time of the dynamic response decreases by 55.5% under the same voltage and 21% under the same travel, and the actuation voltage decreases by 23%.