Through the discussion and analysis of the two traditional computing method of elastic modulus with the normal compressed deformation curve of in-situ direct shear test

which indicate that the real value is bigger than its directly calculated modulus of confined compression and the modulus calculated by the empirical formula of the in-situ load test. A novel integrated method is proposed to calculate the elastic modulus with the in-situ direct shear compression curve. At the same time

the three methods are used to calculate the elastic modulus of highly weathered hornfels in Lingao Ⅲ. The elastic modulus calculated with integrated method of in-situ direct shear compression curve is the sum of the directly calculated modulus of confined compression and the modulus calculated by the empirical formula of the in-situ load test. The calculating principle of integrated method is consistent with the mechanics and deformation mechanism of direct shear test with normal direction load. The calculated value is more close to the real value with which the problem of calculating elastic modulus is resolved effectively in the stability analysis of slope rock deformation.