Abstract: In order to derive the equations of paraboloid surface and its distortion in space, in this paper we put forward a method of paraboloid surface fitting and error estimation by using coordinates of points spreaded around it. Jacobi transformation is used to find correlations among coefficients. Then we introduce a method to transform general conicoid to standard paraboloid equa- tion. The location, direction and size of paraboloid are obtained. The paper puts forward a novel method of error estimation based on iteration. The results indicate that the precision can achieve 0.1% and has wide applicability.