Abstract:A lot of separate points on the paraboloid have to be measured by electronic totalstation with high accuracy during the installation of engineering construction,the estimation of construction precision and the deformation observation after the construction.The plane equation regress of the paraboloid opening,the calculation of the plane normal vector,the coordinates transformation,the circle center fitting,the movement of coordinates axis and the regress of paraboloid equation are dealt with and the paraboloid equation and its focus are obtained to satisfy the requirements of the engineering construction,accuracy estimation and deformation observation.