End　friction　effect　and　initial　defect　of　sample　both　can　cause　inhomogeneous　deformation,　then　form　macroscopic　shear　band　in　soil　test.　The　triaxial　equipment　of　GDS　is　improved　based　on　digital　image　processing　technique,　and　used　to　do　drained　test　of　sand.　The　strain　nephogram　and　local　stress-strain　complete　curve　at　each　sampling　time　point　are　recorded;　then　end　friction　effect　is　researched.　The　result　shows　that　the　end　friction　has　significant　effect　on　mechanical　properties　of　sand　sample.　The　radial　strain　error　reaches　10%.　The　macroscopic　inhomogeneous　sample　is　got　by　putting　silt　clay　block　into　sand　sample;　and　the　formation　process　of　shear　band　is　tested.　The　evolution　of　shear　band　during　the　loading　process　shows　that　the　discontinuation　of　stiffness　formed　at　interface　of　two　materials;　with　inhomogeneous　deformation　developing,　the　macroscopic　shear　band　is　fully　formed,　so　as　to　fracture.