There are many ways to calculate directional drilling trajectory, but none of them are straightforward in trajectory processing and graphic display. A design method for directional well intersection is created with the connection line between the well point and the target as the reference plane through conversion of co-ordinates for twice. Through comparison with the calibrated average angle method and the minimum radius method, the design method is described with its advantages. This design method can provide errors between the drilling trajectory and the target in real time. Excel based software and graphics are used to track the design, resulting in simple and straightforward directional drilling design and construction. This method has been used to complete more than 100 pairs of intersected wells.