Abstract: In process of large-scale development,there existed big difficulties in wellsite determination and remaining oil potential tapping of Jinghe oilfield.Based on reservoir geological characteristics of Jinghe oilfield,theoretical calculation and numerical simulation method were used to optimized borehole trajectory parameters in 3D horizontal wells.Six sections were adopted in trajectory profile,with build-up rate of 4~6°/30 m,and the frontal distance from target point and offset distance being less than 600 meters and matching with each other.The design analysis and field application of JH17P25 indicated the 3D horizontal wells were beneficial to solving many problems encountered in development and met limitation requirements of friction torque,and then the completion string can be safely run into,with good practical drilling trajectory and drilling index effect.