Abstract: The design,simulation and performance tests of a comb-drive actuator with displacement up to 100μm at driving voltage lower than 75V is presented.As the maximum displacement of comb-drive actuator is restricted by electromechanical side instability namely side pulling effect,analysis of side stability,S,are developed to enlarge the displacement.It was found that the S may increase with the increasing suspension stiffness ratio ky/kx and comb gap,but decrease with the engagement area,while driving voltage decreases with the increasing comb gap.Based on these principles,a comb-drive actuator with small comb gap,high-stiffness-ratio prebent suspension beams,non-initial overlap and linear-engaged-length comb teeth is proposed.Experiments indicate that the actuator resonates at 573 Hz with Q factor of 35.88 and reaches the maximum displacement over 100μm at driving voltage of 71V.