Abstract: The definitions of the planar target and three-dimensional target were extended. The equations of coordinate increment of multi-target three-dimensional wellbore trajectory were established. A model for design of multi-target three-dimensional wellbore trajectory based on restricted optimization was developed. This model can be applied to optimize design of multi-target three-dimensional wellbore trajectory of directional and horizontal wells. The optimal variables contain not only well depth, the change rate of inclination angle, azimuth angle and overall angle, but also the type of segment, which makes optimal solution get better and meet the complicated design.