Abstract: Based on the PFC2D discrete element software, different defective rocks were established firstly, and then the mechanical properties and acoustic emission characteristics of intact rocks, single hole defect rocks, single fracture defect rocks and single hole-single fracture defect rocks were explored. The research results show that the mechanical properties of the rocks with different defects are different. When the area of the defect is the same, the effect of the fracture on the mechanical properties is greater than the effect of the hole. The existence of holes and fractures has changed the characteristics of rock acoustic emission. The detailed changes are in the maximum hits strength (number), the number of hits peaks of acoustic emission, and the strain range of intensive acoustic emission hits. Besides, the effect of rocks with single fracture on acoustic emission characteristics is greater than that with single hole under the same defective area.