How the mechanical parameters of rock change with the development of joints and fractures is still a puzzle. It is hard to measure rock joints accurately at present. Resistivity is an important parameter of rock and its value can reflect the degree of fragmentation of rock. A new method combining measurement method of Young’s modulus with resistivity survey method is proposed in this paper. To determine the variation of mechanical parameters in the process of rock damage, the uniaxial, tri-axial compression tests and resistivity survey on rock specimens are done. The results showed that the values of resistivity were continuously increasing, but Young’s modulus and mechanical parameters were decreasing in the process of rock damage. The relationships between resistivity and mechanical parameters are established based on the experiments in the process of rock damage. Therefore, the damage state of rock and the change of mechanical parameters of rock can be determined according to the variance of resistivity. The study is helpful for design and real- time stability evaluation on rock engineering.