Abstract: In order to solve the problems of high fracture pressure and possible fracture diversion in directional well fracturing,a calculation model for three-dimensional stress field around any directional well trajectory has been set up based on the coordinate transformation method.On this basis,taking into consideration in-situ stress,pore pressure,wellbore fluid pressure,wellbore conditions(inclination,azimuth)and other physical and mechanical properties,etc,a perforation orientation optimization method for directional well was put forward,and analysis of optimum perforation orientation at different deviation angle and azimuth performed.Field application shows that optimized perforation orientation could significantly reduce fracture pressure and improve the effect of fracturing.