Abstract: To solve some problems of silicon etching technique,laser electrochemical etching process,which combines laser direct etching process and electrochemical etching process,is adopted to etch silicon.The characteristic of compound etching technique is investigated.The experiments of micromachining silicon by laser-induced electrochemical etching are carried out with a 248nm KrF excimer laser as light source and KOH solution as electrolyte.Based on the experimental results,basic etching silicon appearances by laser electrochemical etching are researched and the quality problems of transverse effect on etching surface and impacting effect on back surface are analyzed.The quality and verticality of cavities by the techniques are good.At the same time,the etching stop of silicon anisotropic etching in alkaline solution is raveled in the process.As a result,it possesses the ability of machining big aspect ratio microstructure.Besides,this process can transfer pattern without mask.