Abstract: In order to reduce the adverse effects of high geostress on the construction and operation of the engineering, based on the practice of engineering and the research experience of relevant scholars, the constitutive equation of pressure relief blasting is obtained through theoretical deduction. The pressure relief blasting constitutive equation is compiled into computer language and calculated by Matlab software. The results of the analysis are as follows: the pressure relief area of pressure relief blasting is not more than the radius of vibration area (2.73 m), and the effect of pressure relief at a radius of two times of crack zone (1.60 m) is mutated.