Abstract: In order to study the mechanical response and failure characteristics of sandstone at the meso level, this paper first carried out indoor rock compression test and PFC^2D uniaxial macro-meso parameter correlation numerical test based on parallel bond model.Then, the trial-and-error method is used to determine the order of the influence degree of each mesoscopic parameter on the macroscopic mechanical index, and the interaction analysis of significant factors is carried out.Finally, the regression analysis is used to establish the functional relationship between macroscopic and mesoscopic parameters.The main influencing factors of crack evolution and failure mode of rock samples are studied by using the control variable method.The results show that: ①The uniaxial compressive strength σ_c has a complex nonlinear relationship with parallel cohesion c, bond normal strength σ_c and bond internal friction angle φ.; ② Elastic modulus E has a polynomial relationship with bond modulus E ^* and bond stiffness ratio k ^*; ③ Poisson's ratio v is linear with k ^* and friction coefficient μ; ④The tensile strength σ_t has a good linear relationship with c and σ_c.; ⑤The crack evolution and failure mode of rock samples are mainly affected by the bond strength ratio σ_c/c, which is negatively correlated with the number of tensile cracks and positively correlated with the number of shear cracks. With σ_c/c increases, the failure mode of rock samples is characterized by tensile failure-conjugate failure-shear failure.The evolution law and failure form of uniaxial compression σ-ε in laboratory test and numerical simulation are basically the same.