Abstract: order to study interior crack evolution rules in rupture and instability process of concrete specimen, uniaxial compression experiment of concrete specimen embedded with strain brick was conducted, variation rule of internal strain of the concrete specimen with time was studied, and acoustic emission signal characteristics of the samples in the evolution process of loading and fracture were measured and analyzed. The following conclusions are obtained: in the compaction stage, variables in different directions are small and acoustic emission count is low; in the stable crack propagation stage, the internal strain of samples increase stably, local strains in different directions are significantly different and acoustic emission signals also show a steady growth trend; when local fast rupture of concrete appears, strain and acoustic emission signal both increase suddenly; before the critical instability, local deformation increases rapidly and the acoustic emission signals increase dramatically; when fracture appears, local strains and acoustic emission pulse number in all directions reaches the peak.