Aimed at the adhesion phenomenon of coupled ultra thin cantilever arrays in release process,the effect of surface tension of the liquid on the cantilever was researched,using release process by backside wet etching.By changing the liquid environment when cantilevers were released and the cleaning method,the surface tension of the liquid was reduce to avoid the adhesion of the beams.Ultra thin cantilevers with length of 220 μm,width of 10 μm and thickness of 220 nm were fabricated successfully.The yield of these cantilever arrays was up to 100%.