A novel adjustable focal-length optical adaptive micro-mirror based on bi-mental effect is presented. Compared with traditional deformable micro-mirror, micro-mirror fabricated by this method has the advantage of low driving voltage and large driving force. Besides,it is easy to be fabricated. Micro-machining processes such as oxygenation,photolithography, chemical etching and sputtering are experimented. A 4×4 bi-metal adjustable focal-length micro-mirror arrays have been completed. Each unit has an area of 3 mm×3 mm with the thickness of silicon 60 μm and aluminum film 150 nm. Deformable mirror area covers 79% of the total mirror area which is 100%. Dynamic performance of adjustable focal-length micro-mirror is tested using laser wave-front interferometer. Experiment results demonstrate that the micro-mirror can produce uni-directional continuous deformation with the maximum deformation of 15.8 and nonlinearity lag of 27%。It can work at 0～2.5 V with an adjustable focal length ranging from ∞ to 0.036 m.