Abstract: In practical engineering structures, concrete is usually under a multiaxial stress state. Therefore, it is significant to investigate the mechanical behavior of microcapsule self-healing concrete under triaxial compression. In this study, a three-dimensional mesoscopic cohesive crack model of concrete based on the cohesive element is established to simulate uniaxial compression tests and conventional triaxial tests of concrete with different microcapsule content. The result shows that when the uniaxial compressive loading reaches , a small number of microcracks start to appear, leading to the nonlinear behavior of the stress-strain curve. When the uniaxial compression is loaded near the peak point (), the internal cracks of the sample begin to increase sharply. Different from the crack of the sample in uniaxial compression concentrated in the interfacial transition zone, the crack of the sample in triaxial compression is scattered in the interior of the mortar and the interfacial transition zone, and the greater the confining pressure, the more crack in the mortar.