Abstract: Normal plane scanning is an important method in interwell relationship analyses such as drilling trajectory deviation, adjacent well anti-collision and directional well targeting. However, the conventional method has two major defects:(1) it can determine whether normal plane has an intersection with comparison well by identifying whether both ends of comparison well section are on the different sides of the normal plane, which may omit danger points of adjacent well anti-collisions;(2) the iteration method can be used for solving the intersection between normal plane and comparison well but needs complicated calculations in the track interpolation, resulting that the convergence is usually poor. Therefore, a method is developed based on the spatial arc model of well tracking to determine whether the normal plane is intersected with the comparison. An analytical method is proposed to solve the intersection. It does not need interpolation for the comparison well but can obtain accurate calculation results by using a design track node or drilling track measuring point data of the comparison well, thus greatly reducing calculations. Its applicabilities have been verified by application examples.