Abstract:How to improve the accuracy cf terrain correction in mountainous-district gravity survey is an important subject which people have paid close attention to. A new equivalent mass line method fox terrain correction is put forward, which is based on integration knots and integration coefficients in Gaussian integration formula. This method has some advantages such as simple formula, definite physical meaning and high accuracy etc. This method makes a dipping tendency plane fit with surface terrain in each grid element, resulting in better fitting. Furthermore, this method speeds up calculation by automatically consulting a table. It is theoretically illustrated that in the case of similar calculation, the equivalent mass line method results in better accuracy than other methods.