Abstract: Within the meridian plane at any point in the space, the normal equation from the point to the Earth's meridian ellipsoid is established. With the geocentric coordinate at the intersection point of the normal and the meridian ellipsoid as the parameters for calculation, the approximate algorithm and strict algorithm for the geodetic height and geodetic latitude are derived. The approximate algorithm is very simple, which can be accomplished by a hand calculator with the trigonometric function. For any point with the height lower than 36000km, the accuracy of h and B can be better than 31m and 0 17° respectively. Taking the intermediate result by the approximate algorithm as the initial value, the calculation of geodetic coordinates can be transformed into a binary first-order equation that can be solved simply. If PC is used, the calculation of a number of spatial points can be accomplished in a moment and the geodetic coordinates that are the same as the true values can be obtained, which provided a support of new technology for the real-time speedy coordinate calculation for the spacecraft.