Three-axis servo testing machine, rock double shear device and acoustic eluission system were used to test the mechanical characteristics and acoustic emission characteristics of the whole failure process of granite under the action of double shear load. Test results show that: When normal stress is low (＜50 MPa),the double shea stress and strain of the rock are divided into 4 stages, named load adjustment section, elastico deformation section, elastico plastic deformation section and post-peak deformation section. When normal stress is higher (＞50 MPa),the double shear stress and strain of rock show one more section of plastic deformation strengthening section than those when the normal stress is low. The acoustic emission signals at different stages of rock shear failure have obvious characteristics.