Abstract: Hydraulic fracturing is carried on the perforated well, and the fracture breakdown influenced by the perforating parameters is critical to the result of hydraulic fracturing. Based on the rock mechanics, percolation mechanics and plastoelasticity, the perforation mechanical model for low permeability reservoir is established. Using the finite element method, the finite element model is established considering fluid-solid coupling effect and transient effect, then the Newton method is used to solve, the geostress distribution can be obtained after different stages from drilling to cementing, perforation and fracturing. Combined with the rock fracture criterion, the effect of perforation parameters upon initiation pressure can be analyzed. The results may be used as basis to optimize the perforating parameters for the low permeability reservoir.