利用改进的Runge定理引入了外大地水准面和外重力位等新概念 ,建立了关于外扰动位的边值问题 ,该问题同时具备了Stokes问题和Mododensky问题的优点 .作为一个整体 ,讨论了外正高的计算和地面重力的归算 ,给出了在O(T2 )量级的精度下确定外大地水准面、地面以及地球外部重力场的方法 . A new Runge's theorem is introduced to introduce new concepts such as outer geoid and external gravitation, and the boundary value problem of external perturbation bit is established. This problem possesses both the Stokes problem and the Mododensky problem. As a whole, The method of determining the outer geoid, the ground and the gravitational field outside the Earth under the O (T2) accuracy is given by calculating the positive height and calculating the ground gravity.