基于中学物理教学中存在将万有引力公式任意推广使用情况,本文从充分性必要性角度证明了:计算物体对质点的万有引力,只有物体质量是均匀的球对称分布,才可以等效地用质点间万有引力公式正确地计算. Based on the universal popularization of the universal gravitation formula in the physics teaching of middle school, this paper proves from the point of sufficient necessity that the gravitation of the object to the mass point is calculated. Only the mass of the object is a uniform spherical symmetry distribution, The formula is calculated correctly.