Abstract: Considering the important influence of joints on the mechanical behavior of rock mass and the difference in fracture surface morphology, uniaxial compression tests of marble specimens with different openings were carried out. With the help of a high-speed camera, PFC^3D particle flow software, and three-dimensional laser scanning software and instruments, the influence of joints on the mechanical properties and failure characteristics of rock mass is analyzed, and the macro and micro failure characteristics of rock mass from crack initiation to failure are studied. The fracture surface morphology data were scanned, and the JRC value of the fracture surface was calculated by using the first-order root mean square of the morphology curve to explore the morphology characteristics of different types of fracture surfaces. The results show that the mechanical properties of rock mass are related to the joint opening. Under the condition of uniaxial compression, the tensile cracks in the complete specimen develop from the middle of the specimen to both ends, and the shear cracks mainly develop from the end of the specimen to the middle, showing a mode of shear-based and tensile-assisted failure. Due to the stress concentration at the joint tip of the prefabricated joint specimen, micro-cracks initiate at the joint tip and develop towards the end, forming tensile wing cracks and shear wing cracks and penetrating, showing a tensile-shear mixed failure mode. Through the analysis of the morphological characteristics of the fracture surface, it is concluded that under uniaxial compression, the tensile fracture surface JRC is between 7 and 10, and the shear fracture surface JRC is between 11 and 14. The distribution of characteristic values of tensile fracture surface curves is quite different, showing the characteristics of high edges and low middle.