The normal moveout correction is widely used in reflection seismic exploration,and there are many assumptions in the normal moveout correction to determine the reflection point.For example,the exploration depth must be much larger than the offset;the reflection points both the inclined reflector and the horizontal reflector are located at the midpoint of offset;amounts of the normal moveout correction at the inclined reflector are considered to be equal to that at the horizontal reflector;the inclination angle of the reflector is assumed small,etc.The above assumptions will definitely cause exploration errors,so a double elliptic method will be proposed to more accurately determine the reflection point Methods:Since the inclination angle of the reflector is unknown,it is theoretically impossible to uniquely determine the position of the reflection point.The seismic wave emitted from the shot point will be received at the receiver point after passing through the reflection point.If the seismic wave speed in the medium is constant,the possible reflection point is part of the ellipse,but the reflection point cannot be uniquely determined.if the shot point and another receiver point are chosen,the possible reflection point is part of another ellipse.If the reflector is assumed to be a plane,it can be a horizontal plane or an inclined plane with a fixed inclination.The plane is shown a straight line in the plane of the seismic wave ray,and the straight line must be the common tangent of the two ellipses.Combining the two elliptic equations with the tangent equation can determine the positions of tangent points,the positions of the tangent points are the positions of reflection points.This is the method to determine the positions of reflection point by double ellipse.Results: We establish a theoretical model and explore the model with the double elliptic method,and the exploration results agree well with the theoretical model.Conclusions: The double elliptic method was tested by a theoretical model,which proved the validity that double elliptic method determines the positions of the reflection point.An important by-product of the double elliptic method is while the positions of the reflector.are calculated, the apparent inclination angle of the reflector is determined.